When protesters started trying in 2011 to overthrow President Bashar al-Assad of Syria, they were part of a cascade of revolutions, known as the Arab Spring, that aimed to oust authoritarian leaders across the Middle East.

While opposition groups elsewhere experienced swift success, the Syrian revolution devolved into a 13-year civil war that has killed hundreds of thousands, displaced millions and carved the country into competing fiefs.

Mr. al-Assad’s stunning fall finally allows Syrians to feel the joy that their counterparts experienced more than a decade ago in Egypt, Libya, Tunisia and Yemen — the four Arab countries where dictators were toppled far more quickly.

Yet while those four states provided a template for revolutionary success, their trajectories since the Arab Spring also constitute a warning.

In Egypt and Tunisia, new strongmen eventually rose to power, crushing efforts to build pluralist democracies. In Libya and Yemen, rival militias jockeyed for control, leading to civil war and the partition of both countries.

“The people who have survived the last 13 years deserve to enjoy the moment before they worry about the future,” said Alistair Burt, a former minister in the British government who helped spearhead its Mideast policy during the Arab Spring.

“At the same time, we all know the experience of the region since 2011,” Mr. Burt said. “We want to hope for the best but we prepare for something worse.”

The dynamics in Syria make for a particularly fraught transition of power. The Islamist rebel alliance that led the rapid advance on Damascus, Hayat Tahrir al-Sham, is one of several rival opposition groups that must now agree on how to run Syria in the post-Assad era.

While Hayat Tahrir al-Sham is now the most influential group in Syria, it is competing for influence with another Turkey-backed group based in northern Syria, as well as a secular Kurdish-led alliance in eastern Syria that is supported by the United States. And southern Syria is dominated by local rebel groups, including militias led by the Druse minority, an offshoot of Islam.

Once affiliated with Al Qaeda, Hayat Tahrir al-Sham has tried to present itself as a moderate movement that seeks to preserve the rights of Syria’s many minorities, including its Christians, Druse and Alawites, the Shiite sect that formed Mr. al-Assad’s base.

Unless the group, which the United States has designated as a terrorist organization, makes good on that promise, analysts say, it could end up prolonging the civil war: Militias from different minorities may feel obliged to defend their areas from the new central government.

“You can’t tell people that they’re safe: They have to believe it,” said Mr. Burt. “That’s why the conduct of H.T.S. — and all those with guns at the moment in the liberated cities — is so important.”

Foreign powers like Iran, Turkey, Russia and the United States, which support different sides in the conflict, are expected to push to retain influence in the new era, potentially prolonging Syria’s internal disputes.

The role and intentions of Mr. al-Assad’s former generals and security chiefs also remain unclear. They could yet prove decisive in any new power play, as their counterparts did in the countries where leaders were toppled in 2011-12.

After the fall of Hosni Mubarak in Egypt in 2011, the military leadership still controlled the pace of the political transition. After allowing elections, the military later took back power in a popular coup in 2013, ousting Mohamed Morsi, Egypt’s first freely elected president. Mr. Morsi, an Islamist, had himself angered many Egyptians through heavy-handed governance, leading some to lose faith in the democratic process.

Elections were also held in Libya after the ouster of Col. Muammar el-Qaddafi in 2011, but the country has been partitioned since civil war broke out three years later.

In Yemen, the departure of Ali Abdullah Saleh in 2012 was also followed by a civil war, which allowed the Houthis, an Iran-backed movement, to seize the capital.

For years, Tunisia was the most successful of the Arab Spring countries, holding several elections after the downfall of Zine el-Abidine Ben Ali. But Tunisia returned to a form of one-man rule in 2021, when President Kais Saied removed checks on his power and began to restrict the media, weaken the judiciary and exert greater control over the electoral authorities.

Given the complexity of Syria’s internal dynamics, some think that Mr. al-Assad’s departure is more likely to widen the rifts left by the country’s 13-year war, rather than heal them.

But other analysts say that it is precisely because of their wartime experience that Syrians may be able to achieve what their counterparts in Egypt and elsewhere could not.

A side effect of suffering for so many years is that Syrians have had far longer to prepare for this moment and consider how to navigate a post-Assad transition, according to Sanam Vakil, head of the Middle East and North Africa program at Chatham House, a London-based research institute.

That is “what distinguishes this moment for Syria,” she said. “There’s also been a lot of learning, there’s been mobilizing, there’s been activism.”

For now, though, many Syrians say they want to enjoy the euphoria of Mr. al-Assad’s departure.

Mr. al-Assad oversaw a cruel government that threw hundreds of thousands of opponents into dirty, overcrowded prisons, where thousands were tortured and killed. Mr. al-Assad’s forces dropped thousands of barrel bombs on his own citizens and gassed some of them with chemical weapons.

His refusal to relinquish power in 2011 led to a bloody civil war that displaced millions of people, destroyed much of the country and led to the rise of terrorist groups like ISIS.

“No matter what comes next, it won’t be worse than Bashar al-Assad’s regime,” said Hashem Alsouki, a Syrian former civil servant detained and tortured early in the war who later sought safety with his family in Europe.

“Yes, there is concern for the future,” Mr. Alsouki added in a telephone interview. “At the same time, I have faith that we will overcome this stage. Because the Syrian people have learned a lot in these 13 years.”

More than 180 people were killed in a massacre over the weekend in one of the poorest neighborhoods of Haiti’s capital, the United Nations’ human rights chief said on Monday.

A leading Haitian human rights group described the killings as the personal vendetta of a gang boss who had been told that witchcraft caused his son’s fatal illness.

The slaughter began on Friday in the Wharf Jérémie section of Cité Soleil, a sprawling slum in Port-au-Prince, according to the National Human Rights Defense Network, a civil rights group based in the capital.

Older people who practiced Voodoo appeared to have been targeted, according to the group. That assessment was backed by another rights organization and a Cité Soleil resident.

The U.N. High Commissioner for Human Rights, Volker Türk, told reporters in Geneva that at least 184 people had been killed.

Nearly 130 of those who were killed were over 60 years old, according to the U.N., adding that gang members burned bodies and flung them into the sea.

The brutality of the killings reflect a country enduring an “accelerating spiral into the abyss,” said William O’Neill, the U.N.’s human rights expert for Haiti.

Haiti has been convulsed by violence since early this year, when rival gangs banded together in a coalition called Viv Ansanm (“Living Together”) to attack government institutions, including police stations, prisons and hospitals.

The National Human Rights Defense Network said that one of the gang leaders, Monel Felix, ordered the killings in Wharf Jérémie after being told by a priest that Voodoo was responsible for his son’s illness. The child died on Saturday afternoon, according to the widely respected rights group.

The group said that Mr. Felix, who is also known as Micanor Altes, Alfred Mones and by the nickname King Micanor, and his gang affiliates used machetes and knives to commit the massacre.

A resident of Cité Soleil, who asked to remain anonymous for fear of retribution, said the killings began on Friday night and targeted people who practice Voodoo. In some homes, five or six people were killed, the resident said.

The Committee for Peace and Development, another Haitian civil organization, said the dead included some younger people, among them several motorcycle-taxi drivers who were gunned down while trying to save others.

“Mutilated bodies were burned in the streets,” according to a statement by the National Human Rights Defense Network.

Pierre Espérance, the network’s executive director, said the number of confirmed dead was likely to rise.

“The senseless loss of lives and the pain endured by families demand not only our deepest condolences but immediate action,” he said. “We cannot continue to stand by as gangs terrorize the population like this.”

Mr. Felix could not be reached for comment, and there was no evidence that he had made any kind of public statement about the killings.

Haiti’s prime minister, Alix Didier Fils-Aimé, said “every resource” of the state would be used to restore peace.

“This monstrous crime constitutes a direct attack on humanity and the republican order,” he said in a statement. The “machinery of the State will be deployed in all its force and with the greatest speed to track down, capture and bring to justice the perpetrators and accomplices of this unspeakable carnage.”

Wharf Jérémie is one of the most impenetrable gang strongholds in the capital, and the police generally do not go there. The lack of a law enforcement presence delayed the reporting of the massacre, experts who were following the developments said.

Voodoo, which originated in West Africa, is one of Haiti’s official religions. Its practitioners believe that all living things have spirits, including animals and plants.

Brought to Haiti by slaves, Voodoo, also spelled Vodou by scholars and followers, is largely misunderstood in Western popular culture and coexists with Christianity as one of several recognized faiths.

The National Human Rights Defense Network said it was not the first time that Mr. Felix had been accused of killing older people who practice Voodoo. He is believed to have been responsible for the killings in 2021 of 12 elderly female practitioners, the rights group said.

About 5,000 people in Haiti have been killed this year and more than 700,000 displaced as a result of gang-related violence, according to the United Nations. In the spring, the gangs succeeded in forcing out a prime minister.

A separate gang massacre two months ago in a farming town about 60 miles north of Port-au-Prince left at least 115 people dead, human rights groups said.

The bloodshed has continued despite the presence of a U.N.-backed police force, known as the Multinational Security Support Mission, which is composed largely of officers from Kenya.

Last month was a particularly deadly one in Haiti. Three U.S. airliners were struck by gunfire while taking off or landing from Haiti’s main airport in Port-au-Prince. The airport is still closed, and American Airlines decided it would not return to the country at least through next year, The Miami Herald reported.

The massacre underscored the need to bolster the Kenya mission and provide it with adequate resources, Mr. O’Neill said.

With violence in Haiti surging, the United States has asked the United Nations to take over the security mission and turn it into an official peacekeeping operation. The change would allow for a steady supply of funding, personnel and equipment. Russia and China, which have veto power at the U.N. Security Council, have objected to the proposal.

The security mission recently announced that it had expanded its operations, opening a new base that will enable international police officers to work in more locations. The mission said it was committed to safeguarding critical infrastructure, reopening key national roads and creating a secure environment for national elections.

“We wish to call on gang leaders to surrender their weapons and turn themselves in, as their time is running out,” the mission said in a statement last week.

A spokesman for the mission said Sunday that he was not aware of the killings in Wharf Jérémie. A spokesman for the Haitian National Police said he had no further information.

David C. Adams and André Paultre contributed reporting.

Early in Russia’s war against Ukraine, Mykola Kulichenko endured an ordeal. He was abducted as a civilian, survived a Russian execution attempt by a stroke of luck and then climbed out of his own grave by pushing through the dirt heaped above him.

His brothers died beside him, but Mr. Kulichenko had turned his head at the last moment and a bullet passed through his cheek, leaving a hole but not causing life-threatening wounds.

His case elicited widespread shock and sympathy in Ukraine — but it did not shield him from Ukraine’s mobilization system. He received a draft summons in October.

Mr. Kulichenko has used his second lease on life to care for his elderly father and return to raising ducks and chickens on a farm in northern Ukraine. But he said he still has trouble sleeping, as he flashes back to being shot and buried alive then finding his way home with his body covered in bruises and his cheek bleeding and tremendously swollen.

Given the trauma of his ordeal, he doesn’t think he should be drafted into the army. “It was very hard to climb out of my grave,” he said.

“What would it change if I go” to the trenches now, he said, claiming that his presence would have no impact on the fighting. “I would take my life to the front and leave it there, for nothing.”

The summons of Mr. Kulichenko, who is 35, underscores the unpredictable and lopsided mobilization system in Ukraine that leans heavily on recruiting older men.

The policies have drawn criticism from the Biden administration, which has said Ukraine should expand its draft to younger men aged 18 to 25, who are now exempt, to defend hundreds of miles of front line. The need for soldiers is now more acute than the need for weapons, American officials have said.

Ukrainian officials say they cannot draft men in their late teens and early 20s without risking demographic shortfalls in the future, and they have pushed back against the American criticism.

“Ukraine cannot be expected to compensate for delays in logistics or hesitation in support with the youth of our men,” Dmytro Lytvyn, a communications adviser to the president, wrote recently in a post on X. It was another swipe at the pace of Western weapons support, which Ukraine views as tepid and overly cautious.

Mr. Kulichenko’s experience also points to the difficulty Ukraine has had in calibrating the rules governing draft exemptions. He became eligible for recruitment after rule changes last spring eliminated some exemptions for hardship, including for those caring for ailing relatives.

Like a game of Whac-a-Mole, each change knocks out some who enjoyed exemptions while adding others who had not — with civilians left to argue over which hardship was more deserving.

The changes to the law were intended to crack down on draft dodgers who abused the mobilization system by claiming hardship when little actually existed, a practice abetted by corruption in the draft operation.

With the loopholes supposedly plugged, recruitment officials stepped up the draft through the summer. Ukraine does not disclose figures, but military analysts have said an initially promising flow of recruits for the army has since tapered off. Fewer men are entering basic training, and many of them are old or in poor health, military commanders say.

Ukraine plans to draft an additional 160,000 men in the “near future,” the secretary of the National Security and Defense Council, Oleksandr Lytvynenko told Parliament late last month. This number would restore units to 85 percent of their full strength, he said.

But reaching deeper into the pool of older men risks filling the ranks with less motivated and healthy soldiers. Even now, none of the brigades in combat are fully staffed, said Maj. Maksym Zhorin, a commander in the 3rd Assault Brigade. Of the new soldiers turning up, he said, “the quality of personnel has significantly deteriorated recently.”

Ukraine, meanwhile, is falling back at two locations on the front inside the country, in the eastern Donbas region and near the town of Kupiansk in northeastern Ukraine, and it has lost about half of the territory captured in an incursion into the Kursk region of Russia in August.

“We are truly on the verge of a military catastrophe,” Yevhen Dykyi, a military veteran and commentator on the war for Ukrainian media, told radio NV. It is not because of mistakes by the army, he said, but because of the failure to draft enough soldiers.

But aggressive mobilization efforts, mostly aimed at older men in rural areas, have led to a backlash in society. Women have blocked roads to prevent recruitment officials from searching for draft dodgers in some western Ukrainian villages.

Men have slipped across the borders to Europe to avoid the draft, sometimes swimming across rivers. Others simply remain at home, lest they get picked up at a checkpoint or other location.

Parliament has been considering a partial swing of the pendulum back — introducing several overhauls to reduce draft evasion and desertion by restoring exemptions and granting draftees more choice in how they serve. Men are now sometimes allowed to choose or change the units in which they serve, for example.

An amendment passed in Parliament in a first reading on Nov. 20 would grant deferments to civilians whom the Russians had arrested earlier in the war and to those who lost close relatives in the fighting.

If signed into law, Mr. Kulichenko could qualify on both points, though under current rules he is still eligible for the draft.

The issue of whether war injuries should merit an exemption from future service has been a divisive one in Ukraine. Men have returned to serve after suffering more grievous injuries than Mr. Kulichenko. Some have voluntarily returned to service even after their legs or arms were amputated. Such dedication is praised by Ukrainians who view their lives and homes depending on holding back Russian soldiers.

Russians arrested Mr. Kulichenko and his two brothers in March 2022 in their hometown, Dovzhyk, north of Kyiv. The dynamic in the war was the opposite of today — the Russians were retreating from northern Ukraine. The brothers were suspected of planting or helping to plant a roadside bomb that killed several Russian officers, Mr. Kulichenko said. He denied any role in the incident.

The brothers were held for three days in an abandoned sawmill where they were interrogated and severely beaten. With the Ukrainian Army approaching, Mr. Kulichenko said, the Russians decided to shoot the brothers to eliminate evidence of the torture. His ordeal was reported at the time by The Wall Street Journal and later taken up in a war crimes prosecution in Ukraine, in which Russian soldiers were tried in absentia.

Russians loaded the brothers in a truck, drove them into the forest, lined them up beside the grave and opened fire. A bullet passed through Mr. Kulichenko’s cheek and he fell to the ground. He lay still as the soldiers piled on dirt, then clambered out after they left.

The draft summons arrived in October. He said he understands the army “lacks people and that is why they take everyone.”

He has not responded to the letter by appearing at a draft board, and said he does not intend to. He does not want to fight in the war, given what happened to him, he said.

“I didn’t get over it,” he said.

Oleksandra Mykolyshyn contributed reporting.

South Korea’s political dysfunction deepened Monday as its Ministry of Justice barred President Yoon Suk Yeol from leaving the country while officials investigate whether his brief declaration of martial law last week amounted to leading an insurrection.

Oh Dong-woon, the chief prosecutor who heads the office for investigating high-ranking officials, told lawmakers that he had sought the travel ban as the office carries out search-and-seizure operations targeting officials who were involved in the martial law order.

No sitting president has ever been arrested in South Korea, and the order adds to the spiraling fallout of Mr. Yoon’s extraordinary move last Tuesday. Since his short-lived martial law declaration, the country has been thrust into a leadership vacuum, and widespread protests have called for his removal.

The justice ministry’s quick acceptance of Mr. Oh’s request shows how Mr. Yoon’s grip on his own government is coming unglued. Mr. Yoon, a former prosecutor, has gone to extraordinary lengths to keep the prosecutors and the justice ministry on his side as a key governing tool, appointing loyalists to key posts there. Home Minister Lee Sang-min, another staunch Yoon ally who controlled the police, stepped down on Sunday.

But the ban also suggested that the investigators considered the allegations of insurrection against Mr. Yoon serious enough to bar the head of state from leaving the country. Mr. Yoon did not immediately notify the National Assembly of his declaration of martial law, as required by law. Even during martial law, the president has no right to detain lawmakers unless they are caught in the act of a crime — a legal provision law scholars say Mr. Yoon violated when he sent troops into the Assembly to physically remove legislators.

The president can be arrested or indicted while in office if he commits insurrection or treason. Legal scholars were divided over whether Mr. Yoon could continue to run the government as president if he were arrested. Some say that his arrest would mean that he was unable to perform his duties and that the prime minister would step in as an interim president until Mr. Yoon’s fate is decided through trial or impeachment. But others say that unless he was convicted and removed from office through impeachment or resignation, he is still the president and could try to act as one, even from prison.

Opposition lawmakers have accused Mr. Yoon and officials including his former defense minister, Kim Yong-hyun, of staging an insurrection when they sent armed soldiers into the National Assembly in an effort to seize the legislative body after the declaration of martial law. If convicted, the leader of an insurrection would face the death penalty or life imprisonment.

An attempt on Saturday by opposition lawmakers to impeach Mr. Yoon failed after the president’s party boycotted the vote, prolonging the uncertainty over who was at the nation’s helm. South Korea’s defense ministry said Monday in a regularly scheduled briefing that command over the country’s military remained with the president.

South Koreans are unsure who is governing the country with Mr. Yoon largely absent from view. Han Dong-hoon, the chairman of Mr. Yoon’s governing People Power Party, said over the weekend that the president had been excluded from performing his duties. Han Duck-soo, the prime minister, said the cabinet, in consultation with the ruling party, would keep the country running.

Opposition groups have said that the party chairman had no legal basis to exclude Mr. Yoon and accused him of making his own grab for power.

The constitutional crisis is unfolding as South Korea faces a raft of policy challenges abroad and at home, and has raised questions over the health of the country’s democracy. The repercussions spread to financial markets on Monday. South Korea’s currency lost value, and the country’s benchmark stock index tumbled 2.8 percent, a steep drop that added to deeper concerns about the country’s economy.

The justice ministry’s travel ban order came as dissension has emerged in the ranks of the military that stormed the legislature during the few hours of martial law command.

Col. Kim Hyun-tae, who led a special forces unit that was sent into the National Assembly, held a news conference on Monday and told reporters that his troops were victims exploited by the defense minister.

Colonel Kim said he received orders to forcibly remove lawmakers from the Assembly chamber. His commanders appeared to be relaying orders from the defense minister, who said the troops needed to prevent 150 lawmakers — the threshold required to repeal martial law — from gathering in the Assembly, he said.

Mr. Kim, the former defense minister, was taken into custody on Sunday for questioning by prosecutors. He is also barred from leaving the country.

After the martial law declaration, Mr. Yoon’s approval rating dropped by nearly eight points to 17 percent, its lowest level during his term, according a survey released on Monday by Realmeter, a South Korean polling company. His party, which boycotted the impeachment vote, also took a hit, its approval rating dropping by six points to 26.2 percent.

Cage-like trucks fitted with iron bars that appear designed to carry livestock line up every morning at the border between Haiti and the Dominican Republic.

The vehicles at the Elías Piña border crossing are not loaded with cattle, but with Haitians being deported by the Dominican immigration authorities. They include young men, pregnant women, unaccompanied children and some people who have never lived in Haiti.

Since October, more than 71,000 people have been deported to Haiti.

Rose-Mieline Florvil, 24, who lived in the Dominican Republic for less than a year, said immigration agents recently raided her house in Santiago, in the northern part of the country, one day before dawn and said something along the lines of “Black woman, come here.”

“I couldn’t run, because I’m pregnant,” she said.

The extraordinary wave of deportations — Dominican officials say the goal is 10,000 per week — reflects a stringent new immigration policy by a country with a complicated and racially charged history with Haiti.

The two nations share the island of Hispaniola, and the Dominican Republic, the far more prosperous of the two, has sounded increasingly loud alarms about shouldering the burden of what experts say is a failing state next door.

Dire problems in Haiti — surging gang violence, a health infrastructure in ruins and a government with no elected leaders and unable to reverse the country’s slide — have set off an exodus of people seeking security and livelihoods.

As a result, Haitian migrants are using an increasing share of Dominican government services, including public health, officials say.

The Dominican authorities say they have had enough.

“The general feeling of the Dominican population is that we are providing social services greater than what the Dominican Republic is responsible for,” the foreign minister, Roberto Álvarez, said in an interview, “and that the international community has left us alone to attend to Haitian needs.”

Since Haiti’s last president was assassinated more than three years ago, the country has been convulsed by gang violence that has left more than 12,000 people dead and forced nearly 800,000 from their homes. (Nearly 200 people were massacred this weekend by a gang in one of Port-au-Prince’s poorest neighborhoods, according to the United Nations.)

Dominican officials say their country should not serve as an escape valve for a crisis the world has largely ignored. Riding a wave of nationalism, the Dominican president, Luis Abinader, announced the stricter immigration policy in October.

Mr. Abinader said he had warned the United Nations that if the situation in Haiti did not improve, the Dominican Republic would take “special measures.”

In addition to the mass roundups, he said he would beef up controls on the border and deploy specialized units to crack down on the growing numbers of migrants and human traffickers, while respecting human rights.

“We don’t have to offer explanations to respect our immigration laws,” the president said.

But human rights organizations say the removals have been plagued with abuses and a lack of due process.

Eduardo Moxteya Pie, 29, who was born in the Dominican Republic to Haitian parents, said he had a police report showing that he had reported his national ID card, which proved Dominican citizenship, as lost.

Without the card, he was detained last month as he left his agricultural job and was taken to Haiti, where he lives in a shelter.

One 11-year-old boy at a migrant shelter in Haiti said he was caught during an early-morning immigration raid on the house where he had been staying in a town near the border.

A 17-year-old said he had been shot in the leg by a Dominican immigration officer during a raid of his home.

While the Dominican authorities have a right to control their border, human rights activists and deportees say immigration agents are sweeping Black people off the streets, regardless of their residency status.

Migrants have arrived in Haiti injured from beatings, and many others reported having been verbally harassed, said Laura d’Elsa, the protection coordinator for the United Nations’ International Organization for Migration, which helps run shelters along the border.

“Why are all these massive abuses taking place?” she asked. “It is extremely shocking to see, and the most extreme I have ever seen.”

Asked about accusations of mistreatment, the Dominican Republic’s interior ministry, which oversees immigration, requested questions in writing and then did not respond to them.

Mr. Álvarez, the foreign minister, said that of the babies delivered in public hospitals, the share born to Haitian mothers had increased to 40 percent in October from nearly 24 percent in 2019.

About 147,000 Haitian children are enrolled in school in the Dominican Republic, costing about $430 million a year, he said.

The country resents claims by critics that its immigration policy is “racist and xenophobic,” Mr. Álvarez said. “All the countries do it, and none are accused of that.”

The two countries’ history is long and complex. After Haiti’s slaves revolted and formed their own independent Black nation in 1804, they led the entire island for 22 years. The Dominican Republic’s Independence Day marks its rupture not from Spain, the country that colonized it for nearly three centuries, but from Haiti.

Dominican leaders have historically promoted anti-Haitian sentiment. In 1937, Dominican troops, acting on orders of the dictator Rafael Trujillo, massacred thousands of Haitians.

Haiti’s foreign minister noted that the Dominican president chose to unveil the mass deportation plan on Oct. 2, the 87th anniversary of the massacre.

In 2010, the Dominican Republic changed its Constitution to eliminate the right to birthright citizenship for children of undocumented immigrants. Three years later, the country’s constitutional court ruled that the measure could be implemented retroactively — rendering stateless tens of thousands of people born in the Dominican Republic to Haitian parents.

“By racial profiling, they can be picked up and can be expelled from their own country of birth,” said Bridget Wooding, an immigration expert at a migration studies institute in Santo Domingo, the Dominican capital.

In October, shortly after the deportations began, Dominique Dupuy, Haiti’s foreign minister at the time, told a French news station that people were chosen “by the simple fact that they had Black skin.” Some of them were not even Haitian, she claimed.

Ms. Dupuy was forced out of her job a few weeks later by a transitional council running Haiti. Both she and the new foreign minister, Jean-Victor Harvel Jean-Baptiste, declined to comment.

In 2017, the last time a government survey was taken, there were nearly 500,000 Haitians in the Dominican Republic, and experts estimate the number may have doubled since then.

Many experts stress that Haitians work in industries like construction and agriculture that buoy the Dominican economy.

But many Dominicans resent their presence.

“If the international community is not going to assume its responsibility, Dominicans are going to defend what’s ours, our space, our territory, our nation, our identity,” said Pelegrín Castillo, vice president of the Fuerza Nacional Progresista party, which has led the nationalist movement.

Eduardo A. Gamarra, an international relations professor at Florida International University who served as an adviser to a former Dominican president, said the authorities there were right to feel that their international calls for help had gone unanswered.

“Anything really that happens in Haiti has a direct consequence on the Dominican Republic,” Mr. Gamarra said. “I don’t think that people really fully understand that.”

Still, the crush of deportations has overwhelmed nonprofit organizations at the border trying to help migrants.

At the Support Group for Returnees and Refugees, a shelter in Haiti near the Elías Piña border crossing, deported migrants swarm social workers, pleading for help.

José Alberto de los Santos, 17, said migration agents picked him up last month while he was working at a tire shop in Higüey, about 30 miles west of Punta Cana, a Dominican resort town on the eastern coast.

“I told them I was Dominican,” Mr. de los Santos said in perfect Spanish. “They asked me for my papers, and I told them I didn’t have them.”

Ms. Florvil, the pregnant woman, said the neighborhood north of the Haitian capital where she is from is now under gang control, so she has not returned. She makes what she can selling water near the Elías Piña border crossing.

“If we had a president in our country, I don’t think that Luis Abinader would mistreat us the way he is mistreating us today,” she said, referring to the Dominican leader. “He does it because he knows that we don’t have a president who speaks for us.”

Only weeks ago, Sunni Arab nations, led by Saudi Arabia and the United Arab Emirates, were trying to bring President Bashar al-Assad of Syria back into the fold, urging him to break with a weakened Iran.

Mr. al-Assad had already been invited back into the Arab League, an association of Arabic-speaking nations in the region, 12 years after being expelled for his brutal crackdown on the Syrian opposition. Then in September, Saudi Arabia reopened its embassy in Damascus, after nearly a decade of broken relations, an indication of confidence that Mr. al-Assad was there to stay.

Even the European Union had begun to discuss dealing with Mr. al-Assad to curb illegal migration.

But Mr. al-Assad hesitated to turn away from Tehran, even when Iran and Mr. al-Assad’s other main backer, Russia — which kept him in power — were weakened and stretched by wars in the Middle East and in Ukraine.

As late as Saturday in Doha, Qatar, foreign ministers from Arab states, Turkey, Russia and Iran met in vain to try to contain the revolt against Mr. al-Assad and avert the chaos that might ensue with his ouster.

Within hours of that meeting, however, Mr. al-Assad’s fate was sealed, as rebels advanced on Damascus, unseated his government and forced him to flee to Russia. By Sunday morning, Saudi, Egyptian, Qatari and other Arab officials were meeting instead to start thinking through the implications of a post-Assad world in the Middle East, where Iran’s influence is crumbling and the power of Turkey and Israel has been enhanced.

Now everyone is jostling for influence in a key crossroads country, already badly fragmented by years of civil war, and trying to remember the lessons of previous failed efforts in the region at nation-building out of chaos, most obviously in Iraq. Because what has been lost is obvious, but not what is to come.

Geir O. Pedersen, the U.N. special envoy for Syria, who met with the foreign ministers of Russia, Iran and Turkey in Doha, said that they had agreed on trying to work with Syria’s new leaders to form a caretaker government that respects minorities and recreates a central authority for all of Syria.

“The hope is that the armed groups will come together and create a unified Syrian state and not try to retain control over their various territories,” he said in an interview. That would enable the international community to mobilize to allow the displaced and the refugees — nearly half Syria’s prewar population — to come home.

“But I don’t want to be too optimistic,” he said. “It’s a time for cautious optimism but also warnings about the challenges ahead if we don’t pull this together.”

The risk is that the various Syrian armed groups will keep control of their current territories and fight each other for primacy — as happened in Afghanistan — preventing the emergence of a unified Syria. That could allow Islamist radicals to take advantage of another chaotic, failed state that can threaten not only Israel but Sunni monarchies of the Gulf.

The Sunni states have traditionally opposed the reach of Shiite Iran; Mr. al-Assad is an Alawite, a splinter form of Shiite Islam.

Among the biggest uncertainties are the true nature and ambitions of Hayat Tahrir al-Sham, an Islamist group once closely allied to Al Qaeda, and its leader, Abu Mohammad al-Jolani. Mr. al-Jolani, 42, broke publicly with Islamic State and Al Qaeda and has been saying all the right things about inclusiveness. But in the areas his group controlled around the city of Idlib in northeastern Syria, the group has governed with a conservative and at times hard-line Sunni Islamist ideology.

As Mr. al-Jolani’s group moved on Monday to exercise power in Damascus, Mr. Pedersen said: “Syria cannot be governed like Idlib. No armed group or community can have monopoly.”

Turkey, a key regional player that has supported the group, has its main interests in northern Syria. It created its own buffer zone along the border there and has been fighting Syrian Kurds, whom it considers an enemy of the state. Whether Turkey will cede control of that area is doubtful, but it is sure to have significant influence in any new Syrian government.

The Syrian Kurds have been supported in part by the United States, which has a small number of its own troops on the ground, fighting the remnants of ISIS. That puts Turkey in opposition to the U.S. on the Kurds, even as they pursue the same goals of stability in post-Assad Syria.

Taking advantage of the chaos, on Monday Turkey announced that its allies had seized the town of Manbij from the American-backed Syrian Kurds.

“It will be key to see how Turkey handles its Kurdish problem, which is the main reason it got involved with Syria in the first place,” said Lina Khatib, an associate fellow at Chatham House. “If it is pragmatic, it will have great influence in Syria’s politics and might pave the way for so many Syrian refugees to return home.”

Turkey is hosting nearly four million Syrian refugees who fled Mr. al-Assad’s brutal crackdown, and the economic and social costs of that generosity have become major political issues for President Recep Tayyip Erdogan.

Asli Aydintasbas, a Turkish expert at the Brookings Institution, said the fall of Mr. al-Assad was a win for Turkey and a loss for those who tried to normalize with him.

“For Turkey, this is not about the border but about winning Syria,” she said. With its connections to the opposition both inside Syria and outside, “Turkey will benefit politically from pushing out Iran and economically from reconstruction.”

As for Russia, which supported Mr. al-Assad, it has suffered “an enormous reputational blow,” even if it does manage to hold on to its naval and air bases in Syria, said Hanna Notte, who studies Russian policy in the region. While Sunni Arabs may have loathed Russia for saving Mr. al-Assad in 2015, she said, “Putin got some respect for standing by an ally and showing up the Americans. But now Russia’s lost its leverage.”

Israel, too, has its own interests, sharing a border with Syria and having annexed the Syrian Golan Heights. It has tried to disrupt the flow of Iranian weapons and money through Syria to Hezbollah in Lebanon and Hamas in Gaza and the West Bank. Israel tolerated Mr. al-Assad for a long time, said Natan Sachs of the Brookings Institution, believing that his efforts to contain Islamist radicalism outweighed his help to Iran.

Now Israel has already moved to seize the buffer zone on the Golan Heights and bombed chemical weapons depots inside Syria to keep them out of the hands of extremists. It is watching carefully, fearing a chaotic Syria that could foster more terrorist groups who despise Israel.

“The questions are open — is the moderation real or not,” Mr. Sachs said, referring to the rebels, “and to the degree it’s real, does it apply to Israel?”

Israel also sees the fall of Mr. al-Assad as a welcome blow to Iran and Hezbollah, raising the chances of better relations, once the Gaza war ends, with Arab states like Saudi Arabia and the United Arab Emirates, which are also wary about Islamists.

Ms. Khatib, from Chatham House, is optimistic. She sees the possibility of a major change in the regional order, no longer dominated by Iran and its allies.

Israel, she said, “can move, if it is careful, from a country striving for alliances with its Arab neighbors to one setting the agenda,” opening up the possibility of further normalization with Arab countries.

“It will take a long time to play out, but there is a trajectory in the region beyond the status quo ante, where Iran and nonstate actors were the spoilers,” she said.

She accused him of isolating her during rehearsals and filming. Of grooming her for three years, when on Saturday afternoons he would touch her sexually. When it began, he was 36. She was 12.

Five years ago, the French actress Adèle Haenel shocked the country’s film world when she spoke out about the director Christophe Ruggia, who had cast her as the lead actor in a 2002 film about an incestuous relationship.

On Monday, the case went to court, marking the first major #MeToo accusations in France to proceed to trial. Mr. Ruggia, 59, is charged with aggravated sexual assault against a minor. If he is found guilty, he faces up to 10 years in prison as well as a fine of up to 150,000 euros, about $190,000.

Mr. Ruggia has repeatedly denied the allegations, saying that his relationship with Ms. Haenel was strictly platonic. Testifying in court on Monday, Mr. Ruggia characterized the accusations that he had touched her sexually as “pure lies.”

Throughout his testimony, Ms. Haenel seemed tormented, her hands agitated, her teeth grinding, her face wracked by tics.

When it was her turn to testify, she described how she had dissolved into self-loathing and depression after years of feeling trapped in a relationship with Mr. Ruggia, in which he repeatedly touched her sexually. He frequently professed his love for her, she said, and would tell her that no one could understand it because she was a child.

“He acted like he was the victim of this story and it was my fault,” she said before turning to him and saying, “I am looking at you Mr. Ruggia: You are a big liar.”

After Ms. Haenel first told her story to the French investigative outlet Mediapart in 2019, it inspired heated conversations about the country’s film industry and sex with minors, and how the French justice system treats sexual abuse complaints.

At the time, Ms. Haenel was a rising star, praised for fierce yet sensitive performances that had earned her two Césars, the French equivalent of the Oscars. In the United States, she rose to fame with “Portrait of a Lady on Fire,” her final role before she announced her decision to boycott the industry.

Mr. Ruggia was a relatively unknown director before the allegations. But in the insular world of French cinema he had a reputation for making films about social justice and for defending migrants and human rights. He spoke up on behalf of workers in the industry, leading him to take on a prominent role in the French directors’ association.

Ms. Haenel, 35, said she decided to speak out about what happened to her after watching a 2019 documentary about the pop star Michael Jackson’s relationship with two young boys, and learning that Mr. Ruggia was working on a film with two teenage actors at the time.

“It’s a responsibility for me,” she said in a Mediapart video interview that year. “I work. I have projects going on. I am comfortable, materially. I am not in the same precarious situation as most of the people this happens to.”

Still, she had gone 15 years without speaking publicly about the abuse, and had never gone to the police. That was because, she explained in the video, she felt there was “systemic violence against women in the justice system.”

“Justice ignores us,” she said, “we ignore justice.”

Days after the article was published, the Paris prosecutor’s office opened a criminal case. Ms. Haenel decided to participate in the process. It became a four-year investigation.

In a letter sent to Mediapart, Mr. Ruggia denied the allegations but said he understood the powerful influence he may have had on Ms. Haenel as the director who first discovered her talent. “At the time, I did not see that my adulation and the hopes I placed in her could have appeared to her, given her young age, as painful at certain moments,” he wrote. “If this is the case and if she can, I ask her to forgive me.”

Ms. Haenel’s decision to speak publicly sparked discussions, but it did not result in political or structural changes in the industry. While #MeToo quickly toppled several powerful men in Hollywood after the movement began in 2017, in France there was strong resistance. “Many artists blurred, or wanted to blur, the distinction between sexual behavior and abuse,” Ms. Haenel said in a 2020 interview with The Times.

Just a few months after Ms. Haenel spoke out, the director Roman Polanski was given the most prestigious award at the annual César ceremony — best director. Mr. Polanski was convicted in 1978 of having unlawful sex with a 13-year-old girl in the United States.

Ms. Haenel, who was nominated for best actress, staged an unplanned protest at the ceremony, standing up in her navy gown, turning her back to the stage, making a zero with her fingers and shouting “Shame!” before leaving the theater.

In a letter published in a French culture magazine in 2023, Ms. Haenel explained her decision to leave cinema — an industry she said protected sexual abusers and would rather victims “disappear and die in silence.”

“I am canceling you from my world,” she wrote.

“The reception in France to Adèle Haenel’s declarations in 2019, in reality, testifies to the resistance in the industry,” said Geneviève Sellier, an emeritus professor of cinema studies at Bordeaux Montaigne University and the author of “The Cult of the Auteur.”

“She was alone. She was followed by almost no one.” She added, “In the end, the price she paid was extremely heavy because she no longer works in cinema.”

The #MeToo movement in France’s movie business was rekindled last year when the actress Judith Godrèche accused two directors of sexually abusing her when she was a child actress.

Her public announcements came shortly after a television investigation into France’s most decorated actor, Gérard Depardieu, who has faced and denied several accusations of sexual misconduct. The documentary included footage of him making crude and sexist comments about a prepubescent girl during a 2018 trip to North Korea, which caused another shock wave in France.

A couple of months later, two women filed a lawsuit against Mr. Depardieu accusing him of sexual assault during the shooting of a film in 2021, which he has denied. He was due to appear in court last month, but his lawyer said he was too ill to attend. His trial has been postponed to March.

At Ms. Godrèche’s prompting, the French lower house of Parliament launched a committee to examine sexual violence in the film and other artistic industries in France.

Perhaps because of Ms. Haenel’s public criticism of the justice system in France, the police investigation into her case has been extremely rigorous and detailed. The overview of the case by the investigative judge is 35 pages.

“Justice treated Adèle Haenel’s case efficiently and allocated resources you don’t find in many cases,” said Marine Turchi, the Mediapart journalist who broke the story.

The investigating judge interviewed 26 people, including 11 members of the cast and crew of “The Devils,” Mr. Ruggia’s 2002 film in which Ms. Haenel plays an autistic child in an incestuous relationship with her brother. Several crew members said the director had an “intense,” “ambiguous” and “unhealthy” relationship with the actress, isolating her from others. Some reported seeing him kiss her on the face and cheeks.

Others, such as Ms. Haenel’s co-star Vincent Rottiers, said they had not seen any inappropriate behavior from Mr. Ruggia. The film’s producer and one of its editors also said they saw nothing out of the ordinary.

After the film was shot, Ms. Haenel regularly visited the director’s apartment to watch films, so he could teach her the classics, she said. While there, he caressed her thighs, working his way up to her genitals, kissed her on the neck and put his hand under her T-shirt to stroke her breasts and her belly, she told the police.

“Christophe was telling me that he was in love with me and that the age difference was a curse to him and that unfortunately I was an adult in the body of a child,” she told the police.

Ms. Haenel said that she refused to see Mr. Ruggia after 2004, and the police have collected two letters that he sent to her years later. In them, he wrote that his heart was “exploding in his chest” after he saw her on the street one day, that his longing for her was like a “wound” and that his love for her had “always been sincere.”

After the Mediapart investigation, Mr. Ruggia’s new film involving the teenage actors, “The Emergence of Butterflies,” was put on hold and he was ejected from the French directors’ association. He told the police that other projects he had in the works had also been put on hold because of the investigation, and that he had lost his job at a prestigious theater school. He is living on welfare in Brittany, close to his parents’ home, he added.

The trial is scheduled to last about two days.