Lebanon’s fractured Parliament overcame more than two years of gridlock on Thursday to select a new president, a critical step toward bringing stability to a country attempting to recover from economic catastrophe and a devastating war.

Lawmakers elected Gen. Joseph Aoun, the commander of the Lebanese military, by an overwhelming majority in the second round of voting, with 99 votes in the 128-seat Parliament, after he failed to achieve the necessary tally in the initial round. It was a breakthrough in the effort to form a government after more than two years of weak caretaker rule.

“Today, a new phase in Lebanon’s history begins,” General Aoun said during his victory speech.

The vote was seen as a crucial milestone for Lebanon, and people in Beirut, the capital, celebrated with fireworks and gunfire as the results became clear. The crisis-hit nation has endured a series of disasters in recent years, including an economic collapse and a war between Israel and the Lebanese militant group Hezbollah that has left large areas in ruins.

The election on Thursday — which frequently descended into shouting matches — also reflected shifting power balances in the region and came at an unnerving time for Lebanon. In neighboring Syria, an untested government is attempting to chart a path forward after years of civil war. The fall of the Assad regime in Syria and the military defeat of Hezbollah, the militia that has long been Lebanon’s dominant political force, have also meant a sudden loss of power for their patron, Iran.

Lebanon’s international backers, including the United States, have implied that postwar financial support is contingent on the election of a president. According to the World Bank, the Israel-Hezbollah war, which has been suspended during a fragile 60-day cease-fire, has caused $8.5 billion worth of damage and losses in Lebanon.

Since October 2022, when Michel Aoun stepped down as president at the end of his six-year term, the Parliament had voted on a replacement 12 times without success. Under Lebanon’s sectarian power-sharing agreement, the president must be a Maronite Christian.

Hezbollah has been a major roadblock, scuttling votes by walking out of the chamber. But the group was deeply weakened by the war with Israel and analysts noted that it likely felt it had to make concessions because of the scale of Lebanon’s financial need.

Hezbollah’s parliamentary bloc remains strong and could have thwarted General Aoun’s election, but it ultimately threw its weight behind him on Thursday. The group’s candidate dropped out on the eve of the election, a widely expected move. Analysts said that the war had left Hezbollah little room to maneuver politically.

“He encapsulates the shift in the power balance in Lebanon,” said Mohanad Hage Ali, a senior fellow at the Carnegie Middle East Center in Beirut.

General Aoun is now expected to appoint a prime minister, in consultation with Parliament, and the prime minister — who must be a Sunni Muslim — will then form a government. With no faction holding a majority, it is unclear how long that will take. General Aoun said he would seek consultations as soon as possible.

The new president, who is not related to Michel Aoun, is considered by analysts to have U.S. backing and is widely respected in Lebanon. He has led the armed forces since 2017, and they are the single national institution that enjoys cross-sectarian support.

“He is seen as an acceptable figure by all of Lebanon’s political elite,” said Lina Khatib, an associate fellow at Chatham House, a London-based research organization. “This is tied to the perception in Lebanon that the Lebanese Army is an institution working in the national interest.”

The U.S. and Saudi ambassadors attended the vote on Thursday, along with France’s special envoy to Lebanon and other foreign diplomats. A flurry of diplomatic efforts preceded the vote, including a visit earlier this week by Amos Hochstein, the top U.S. envoy in the region, who met with General Aoun and called on lawmakers to break the political gridlock.

The election of General Aoun, who will resign as army chief, will require an amendment to the Constitution, a step that has precedents but that led to raucous debate in the Parliament. Senior civil servants are required to resign two years before standing for public office.

Dozens of lawmakers cast protest votes in the first round, including one for “Joseph Amos Bin Farhan,” a jumbling of General Aoun’s name with those of the U.S. and Saudi envoys that reflected anger among some lawmakers over international influence.

Diplomats have said that they hope that General Aoun’s military career will allow him to exercise continued sway over the army and fully implement the U.N. Security Council’s Resolution 1701 — a 2006 agreement that ended the previous Israel-Hezbollah war but failed to keep the peace. They hope it will be a blueprint for a longer-term peace once the current cease-fire ends.

During his victory speech, General Aoun pledged that only the Lebanese state would have weapons, prompting applause in Parliament. Israeli officials have said they hope the Lebanese Army will crack down on Hezbollah’s activities in southern Lebanon.

“I hope that this choice will contribute toward stability, a better future for Lebanon and its people and to good neighborly relations,” Gideon Saar, the Israeli foreign minister, said on social media.

Addressing Parliament and the nation, General Aoun tried to reassure the Lebanese people that he would help restore stability to the country, pledging to empower the state and fight corruption. He also spoke directly about the devastation of the Israeli war with Hezbollah.

“My pledge is to rebuild what Israel destroyed,” he said.

Aaron Boxerman contributed reporting.

Venezuela’s popular opposition leader, María Corina Machado, was briefly detained by adversaries during an antigovernment protest in Caracas on Thursday, according to a statement on X by a political aide. But she was soon released.

Ms. Machado was “violently intercepted as she left the gathering,” her party said on X. “Regime troops shot at the motorcycles that were transporting her.”

The country’s autocrat, Nicolás Maduro, is set to be sworn in for a third term as president on Friday.

Ms. Machado had been living in hiding in Venezuela amid threats of arrest from government officials, and this was her first public appearance since August. She had called for gatherings around the country, and in cities around the world, to protest Mr. Maduro’s inauguration.

Thousands turned out to support Ms. Machado at an event in Caracas on Thursday, all risking government detention. There, the opposition leader stood atop a truck while supporters shouted, “Freedom! Freedom! Freedom!”

On X, the political aide, Magalli Meda, said that as Ms. Machado was leaving the gathering, she was knocked off her motorbike.

“Firearms went off at the event,” Ms. Meda said. “They took her away by force.”

During her brief detention, “she was forced to record several videos and was later released,” she added. “In the next few hours she herself will be the one to address the country to explain what happened.”

Representatives for Ms. Machado declined to say who detained her. The event was full of government security forces, who are often backed by members of armed gangs know as colectivos.

Venezuela’s interior minister, Diosdado Cabello, speaking in a television interview, called the capture “a lie” and accused the opposition of inventing it to attract attention.

The country’s opposition, as well as the United States and other countries, say that Mr. Maduro had stolen a recent election and that the real winner was Edmundo González, a former diplomat who has Ms. Machado’s backing.

Mr. González has been living in exile since September.

Before her detention, Ms. Machado told her followers, “This force that we have built and that grows every day has prepared us for this final phase.”

“Whatever they do tomorrow,” she said of the Maduro inauguration, “they’ve just buried themselves!”

About 2,000 people have been detained in Venezuela since the July 28 election, including, in recent days, Mr. González’s son-in-law, Rafael Tudares, as well as Carlos Correa, the director of a high-profile nonprofit organization, Espacio Público.

Hermann Goering, Hitler’s right-hand man, survived the cut. His bottles of wine — part of a collection seized by the Soviet army as a trophy at the end of World War II and deposited in a labyrinthine underground cellar in Moldova — are still on display.

A gift of 460 bottles given in 2013 to then Secretary of State John Kerry when he visited the former Soviet republic is also there, kept in his name in a cubbyhole in the vast system of tunnels. (The State Department reported their value as $8,339.50, which might explain why Mr. Kerry chose to leave them behind.)

But President Vladimir V. Putin of Russia, who twice visited the cellars operated by the state-owned Cricova Winery, has been banished. His wine bottles, along with his photograph, have been removed from view in the vast complex of underground tunnels that twist and turn over 75 miles under vineyards north of the Moldovan capital, Chisinau.

After Mr. Putin began a full-scale invasion of Moldova’s neighbor, Ukraine, in 2022, the winery “got lots of questions that we could not answer about why he was still here,” said Sorin Maslo, the director.

Mr. Putin’s wine collection, a gift to him from Moldova’s former communist president, has not been destroyed, Mr. Maslo said. The bottles, he added, had been moved to a dark, sealed-off corner of the cellar so that “nobody has to deal with him.”

For a country that takes viniculture very seriously, the banishment of Mr. Putin’s bottles sent a blunt divorce message in a long-strained relationship that Moldova recently declared doomed by irreconcilable differences.

It was part of a decisive rupture that in October led voters to endorse, albeit by a tiny majority, changing Moldova’s Constitution to lock in the country’s exit from Moscow’s sphere of influence and align more closely with Europe.

That course was first set in 2006 when Russia, previously Moldova’s biggest wine export market, imposed a two-year ban on imports from Cricova and other Moldovan wineries during an early tiff between Moscow and Chisinau.

The ban, Russia claimed at the time, was needed to protect consumers from impurities, but it was widely seen as retaliation for demands by Moldova that Russia stop supporting the breakaway Moldovan region of Transnistria.

Russia lifted the ban on Moldovan wine the following year but reimposed it in 2013 after Moldova expressed a desire to forge closer ties with the European Union.

The 2006 embargo forced Moldova’s winemakers to look West for markets and convinced them that “the future for us is definitely not Russia,” said Stefan Iamandi, the director of the National Office for Vine and Wine in Chisinau. Russia, which once accounted for 80 percent of Moldovan wine sold abroad, today buys 2 percent, with more than 50 percent going to the European Union. That has meant moving away from sugary “semisweet” wines produced to suit Soviet palates, to high quality wines that regularly win international prizes.

Georgia, another former Soviet republic, was hit by a similar ban in 2006, prompting its winemakers, too, to start looking West.

Wine has for centuries played an outsize role in Moldova’s relationship with Russia, both lubricating and at times poisoning ties between what, until the collapse of the Soviet Union in 1991, were two parts of the same country.

Moldova has traces of grape cultivation stretching back thousands of years, and started exporting wine to Russia in large volumes in the 14th century. This trade expanded dramatically during the Soviet Union when vineyards in Moldova and Georgia provided much of the wine consumed in Russia.

Moldovan wine enjoyed a particularly good reputation. That became a curse when the last Soviet leader, Mikhail Gorbachev, identified alcoholism as one of the Soviet Union’s most serious problems in 1985 and overzealous Communist Party officials ordered that vineyards in Moldova, Georgia and Crimea be destroyed. Moldova ripped up some vines but left most intact, arguing that it needed grapes to make fruit juice.

Before that, Moscow and Moldova bonded over booze.

In 1966, when Yuri Gagarin, a Russian cosmonaut and the first man in space, visited what was then a Soviet republic called Moldavia, he spent two days at the Cricova Winery, where, like other visitors, he was offered wine tastings.

Legend has it that he tasted so much he had to be carried away in a stupor.

Mr. Maslo said that is not true, insisting “Gagarin was not drunk” and was just happy at the quality of the wine.

Unlike Mr. Putin, Mr. Gagarin has not been canceled and is still celebrated in Cricova’s underground cellar with a photograph and a plaque. Displayed proudly on the wall is the handwritten thank-you note he left at the end of his 1966 visit: “In these cellars is a great abundance of wonderful wine,” he wrote. “Even the most fastidious person will find here wine to their liking.”

There is certainly a lot to choose from. The vast wine cellar, housed in the shafts and meandering tunnels of a former limestone mine, holds 1.2 million bottles. The tunnels, lined with wine racks, barrels and large wooden casks, are part of a sprawling subterranean city. It has a wine shop for tourists, tens of thousands of whom visit each year, a movie theater and opulent tasting and banqueting halls for visiting dignitaries.

Tunnels dug for limestone miners have become streets, each one named after a type of wine — Cabernet, Pinot Noir, Champagne and local varieties like Feteasca. There are street signs and traffic lights. Electric buggies transport winery workers and visitors around the labyrinth. The temperature is constant at around 55 degrees Fahrenheit, and the humidity of the air is always the same.

Also unchanging is the tedious labor of a team of workers who spend each day deep underground methodically turning bottles of sparkling wine stored neck down in high racks. The motion ensures that sediment gathers at the neck and can be easily removed before final bottling. All the bottle-turners are women because men, Cricova’s management decided, get bored too easily and take too many breaks.

Lybov Zolotko, who trained for the job by twisting her wrists in a bucket of sand, said she turns at least 30,000 bottles a day. It is boring work, she conceded, “but you get used to it” — and it pays a steady salary in a country where stable jobs are hard to come by.

Another Moldovan winery, Milestii Mici, has even longer tunnels — they stretch 150 miles — but Cricova has had far more high-profile visitors, including Mr. Putin, who celebrated his 50th birthday in its cellars; President Volodymyr Zelensky of Ukraine; and Angela Merkel, when she was still chancellor of Germany.

Tatiana Ursu, employed at Cricova for 30 years, has hosted a stream of dignitaries in the underground tasting rooms and banquet halls. Particularly warm, she said, was a 2002 visit by Mr. Putin, who was on excellent terms with Moldova’s president at the time, Vladimir Voronin, Europe’s first democratically elected Communist Party head of state after the collapse of communism.

The visit used to be a source of pride for the winery, Ms. Ursu added, but “not so much any more” given that the seemingly mild-mannered man she met in 2002 — who had only been in the Kremlin two years when he visited — has since turned against Moldova.

Mr. Voronin gave the Russian president a bottle of wine in the shape of a crocodile, she recalled.

Mr. Putin and others in the Russian delegation did not drink too much and left a good impression on their Moldovan hosts, Ms. Ursu recalled.

“They were all friends back then. It was a different time,” she said.

In easier times for Egypt’s refugees, Azza Mostafa, a pro-government TV anchor, had nothing but generous words for the many thousands of Syrians who had built new lives in Egypt after their own country imploded into civil war in 2011.

“I’d like to say to our Syrian families and our brothers in Egypt,” she said in a 2019 broadcast, “you’ve truly brought light to Egypt.”

But there she was on her show in June, fulminating against Egypt’s growing number of outsiders — an echo of the country’s leaders, whose policy toward refugees and migrants has hardened as they wrestle with an economic crisis made worse by wars in neighboring Gaza, Sudan and Libya.

“This has become unbearable,” Ms. Mostafa said, accusing migrants of driving up rents and promoting female genital mutilation. “There are many acts of overstepping bounds. Is that acceptable? After we opened our country for them?”

Egypt long made it easy for foreigners of all kinds to live and work in the country, largely without interference, whether they were refugees, migrant workers or Westerners escaping coronavirus lockdowns.

The past 13 years have brought a near unbroken stream of newcomers fleeing conflict to the country that is known among Arabs as the “mother of the world.” That includes not just Syrians but also Sudanese, Yemenis, Eritreans and, most recently, Palestinians from Gaza.

Egypt’s lax immigration rules meant many never formally registered as refugees or received official permission to stay long-term, yet managed to stitch themselves almost seamlessly into the country, supporting themselves and sometimes starting businesses.

Since Sudan’s civil war drove a surge of refugees to Egypt starting in 2023, however, the impoverished government in Cairo has complained louder and louder about the burden of foreigners. It rapidly tightened its policies — hoping, analysts and diplomats say, to win more support from international backers eager to prevent migration to their own countries.

Egypt says it spends $10 billion each year on its nine million refugees, according to officials and government-controlled media (though experts say both numbers are greatly exaggerated), all while Egyptians endure soaring prices and subsidy cuts.

Years of government overspending, reliance on imports and policies that neglected private-sector growth left the country’s finances in precarious shape before the wars in Ukraine and Gaza sent them crashing. Egypt lost $7 billion in crucial revenue from the Suez Canal in 2024 as the conflict in Gaza has squeezed shipping in the Red Sea, according to government officials.

With Egypt deep in debt and hard-pressed to pay for imports such as wheat and energy, the currency has crashed, while some goods have become difficult to find.

Ahmed Abu Al-Yazid, the head of a government-owned sugar firm, the Delta Sugar Company, blamed refugees for a sugar shortage that experts link to the economic crisis. The president accused them of draining Egypt’s precious water. On social media, pro-government accounts — some of which appeared to be fake — accused Sudanese refugees of driving up rents and promoting female genital mutilation.

A crackdown soon followed the accusations, according to migrants, refugees and their advocates.

Sudanese refugees have been rounded up in police sweeps, detained and summarily deported. Syrians who have lived in Egypt for years have been told to pay thousands of dollars to stay. Many remain hesitant to return, despite the fall of the Assad regime in December, until the situation stabilizes.

Foreign workers from Asia and from other parts of Africa now face extra hurdles to keep their legal status, and in some cases, have been arrested to compel them to pay high fees, advocates say.

Last month, Egypt passed a law that would hand responsibility for screening refugees and others to the government, instead of to the United Nations refugee agency.

Government officials said the measure would ensure a wide array of refugee rights. Critics of the move, however, said that it would become far harder for refugees to gain protection or access to health care and schools. The law also empowers the government to revoke refugee status on vague grounds such as breaches of national security, political activity or violations of Egyptian social customs.

Abu Saleh, 32, a Syrian who works in a small Cairo grocery, said he had lived in the city for 13 years “without a single issue” until he discovered in July that he could no longer enroll his son in school without a residence permit.

Just to renew his family’s tourist visas, he said, he was told that he would have to return to Syria and pay $2,000 per person in fees — a process he would have to repeat every six months.

“Egypt has been there for us all along,” said Abu Saleh, who asked to be identified by the name he uses around town to avoid possible repercussions. “I’d like to appeal to the government of Egypt: Give us residence, even if it’s a little more expensive. We’re facing tough conditions.”

Egypt has not explained its hardening attitude toward foreigners. But analysts and migrant advocates tie it to the economic crisis, which has generated widespread bitterness and undermined President Abdel Fattah el-Sisi’s rule.

The newcomers make convenient scapegoats for Egyptians’ hardships, rights groups say. Immigration fees, charged in dollars, can supply some of the foreign currency that Egypt badly needs. And foreigners are also valuable pawns in Egypt’s quest for more financial support from its international partners, rights groups say.

“They think, ‘How can these people be useful for the government?’” said Nour Khalil, executive director of the Refugees Platform in Egypt, which advocates migrants’ rights.

The U.N. refugee agency counts about 818,000 registered refugees in Egypt, who are entitled to free public health care and education. There are likely many more unregistered refugees, though analysts and aid workers dispute the figure reaches nine million.

The benefits that registered refugees receive mean that Egypt “is treating them like Egyptians, despite the fact that we are not a rich country,” the foreign minister, Badr Abdelatty, said at a news conference last month. “There is no country in the world assuming these responsibilities and challenges like here in Egypt. We don’t have one single refugee camp — they are fully integrated in society.”

Refugee advocates agree that Egypt needs more resources. Unlike other countries in the region, including Jordan, Lebanon and Turkey, where the United States, the United Nations and the European Union have poured billions into supporting refugees, Egypt has not received significant funds to help house Syrian or other refugees.

That is changing.

As the war in Gaza has pounded Egypt’s finances, Western backers have rushed to Egypt’s aid, anxious to prevent an economic collapse in the Arab world’s most populous country, analysts and diplomats say. A crash in Egypt could further destabilize the Middle East and send a deluge of migrants across the Mediterranean Sea to Europe, where there is heavy public pressure to restrict migration.

The European Union pledged a fast-tracked $8 billion aid package to Egypt in March, echoing deals the bloc has struck with Mauritania, Tunisia and Turkey that funded migration enforcement in those countries.

Other backers, including the International Monetary Fund, have sent billions more to stabilize Egypt’s economy.

Critics say the European pact with Egypt, like the bloc’s other migration deals, is enabling rights abuses by rewarding Mr. el-Sisi’s authoritarianism and potentially funding the current crackdown on migrants.

Groups including Amnesty International and the Refugees Platform in Egypt have documented what they say is a pattern of mass arbitrary arrests and unlawful deportations of Sudanese refugees — some detained as they were smuggled across the border, others rounded up during random sweeps of predominantly Sudanese neighborhoods.

Some Syrians, too, have been expelled, Mr. Khalil of the refugees platform said. His group has also documented more than 50 arrests of foreign workers, some of whom already had residency, who were held until they paid $1,000 in fees and fines, he said.

An atmosphere of fear has brought throngs of Sudanese to the doorstep of the U.N. refugee agency in Cairo, seeking formal protection. But refugee status can take months, if not years, to obtain: Appointments to begin the process are not available until late 2025. And some of the Sudanese who have been detained and deported, Mr. Khalil said, held some form of U.N. identification, casting doubt on whether the organization could guarantee security.

Among those waiting outside one morning was Mohammed Abdelwahab, 36. By the time he and his family tried to cross the border from Sudan this spring, Egypt had tightly restricted what had been free-flowing movement between the two countries, so they resorted to smugglers instead.

Without legal papers, Mr. Abdelwahab and his 14-year-old son, Mohanad, collected plastic bottles on Cairo’s streets for a living. Mr. Abdelwahab was looking for better work one day in June when Mohanad disappeared.

Twenty days later, Mohanad resurfaced with a WhatsApp message: He had been rounded up with a group of other Sudanese and deported.

Mr. Abdelwahab had been looking for Mohanad in another city. When he returned to Cairo, his wife and three other children had been evicted for nonpayment.

“It’s indescribable,” he said. “Now they’re all camping out here,” he added, referring to his family and indicating the sidewalk in front of the refugee agency, where groups of other Sudanese waited listlessly in the sun.

Emad Mekay and Rania Khaled contributed reporting.

The founder of the website used by Dominique Pelicot to invite dozens of men to rape his wife after he’d drugged her was indicted on Thursday in France on myriad charges, including some related to that case.

If found guilty, he faces up to 10 years in prison and a fine of up to 7.5 million euros, or about $7.7 million.

The site’s founder, Isaac Steidl, 44, was released from jail on Thursday. The investigating judge’s office said he was placed under “judicial supervision,” had to pay a bail of 100,000 euros and was barred from leaving France.

The website he created in 2003, called coco.fr, became notorious in France during the trial of Mr. Pelicot and 50 other men, who were all found guilty last month, mostly for raping Mr. Pelicot’s now ex-wife, Gisèle, while she was heavily sedated.

One of the charges against Mr. Steidl that is related to the Pelicot case is administering an online platform to enable an illicit transaction by an organized gang. Among the other charges he faces are complicity in drug trafficking, complicity in the possession and distribution of child pornography, aggravated pimping and aggravated money laundering.

Mr. Steidl “firmly denies the accusations made against him, and undertakes to cooperate fully to demonstrate his lack of responsibility for the alleged offenses,” his lawyer, Julien Zanatta, told Agence France-Presse.

During the trial, Mr. Pelicot said that he had met all the men in a private chat room on the website called “Without Her knowledge.” Most of the defendants denied ever have seen that particular chat room.

They agreed, however, that they had met him on the site, and then moved the conversation to text messages or Skype to arrange a visit to the Pelicots’ home in southern France, where they joined him in raping his now ex-wife while she was in a deeply drugged state.

The Paris prosecutor Laure Beccuau said in a statement that the website was implicated in more than 23,000 cases in France alone from 2021 to 2024, involving 480 alleged victims. The cases included allegations of sexual abuse of children, pimping, prostitution, rape, drug trafficking, scams and homicides, police and prosecutors said in a statement.

The site was shut down in June after an 18-month investigation that stretched across Europe. Police froze bank accounts in Hungary, Lithuania, Germany and the Netherlands and seized 5 million euros, the Paris prosecutor said at the time.

Mr. Steidl’s home in Bulgaria had been searched at the request of French judges over the course of the operation, the prosecutor’s office said.

Mr. Steidl grew up in the southern French province of Var. In April 2023, the French government agreed to his demand to renounce his French citizenship. Last June, after his site was closed, he was interviewed by an investigating judge in Bulgaria, with French law enforcement officials present.

French nonprofit organizations fighting against child abuse, homophobia and illegal online content had been raising alarms about the site for years. A petition calling for it to be shut down was signed by more than 20,000 people.

“The coco site was a den of pedophiles,” said Sophie Antoine, who works on legal issues and advocacy for the French organization Act Against the Prostitution of Children.

Ms. Antoine said her organization often used it to show child-care professionals “how the ‘darknet’ really is in the open.” Signing up was free and required only a name, age and postal code. Once you were logged in, other users could contact you to chat and make propositions — but once you signed off, those chats were immediately erased, she said.

Pierre Poilievre, the man who is the favorite to become Canada’s next leader, has painted his country as “broken” and ridden with “crime and chaos.” He has derided Prime Minister Justin Trudeau as a “wacko” and his ministers as “crazy,’’ “disastrous,” “incompetent and discredited.”

In Parliament, he called a leftist opposition leader and former Trudeau supporter “a fake, a phony and a fraud’’ and a “sellout.’’ Enraged, the leader stood up from his seat, walked into the aisle, and yelled, “I’m right here, bro.”

“Do it,” Mr. Poilievre shot back as the House speaker struggled to restore calm and pleaded that lawmakers respect “the rules that we have.”

Mr. Poilievre, 45, the opposition Conservative Party leader, has been stretching the rules in Canada’s political discourse with a combative, attack-driven style and an anti-elite, populist message that has been described as authentic by supporters and Trumpian by critics.

So far, it’s worked.

For the past year, Mr. Poilievre and his party have enjoyed a double-digit lead in the polls over Mr. Trudeau and his Liberal Party. If the polls hold, Mr. Poilievre will emerge as the next prime minister in a general election that must be held by October but will most likely be held in the spring after Mr. Trudeau’s announcement on Monday that he would resign as party leader and prime minister once his party decides on a successor.

A career politician long known as a fierce attack-dog for his party, with an instinctive sense of the themes that resonate among voters, Mr. Poilievre has successfully pummeled the unpopular Mr. Trudeau in the past year and made him appear out of touch.

Mr. Poilievre drove the nation’s political agenda by handpicking issues — housing costs, inflation and immigration — that, according to many Canadians, Mr. Trudeau’s government had underestimated or mishandled.

But in a news conference announcing his resignation, Mr. Trudeau said that Mr. Poilievre’s “vision for this country is not the right one for Canadians,” adding that the opposition leader was not offering “an ambitious, optimistic view of the future.”

Whether Mr. Poilievre can cling to his lead in the polls, or even build on it, as voters now get to know him better remains unclear. In the months ahead, the Liberal Party’s choice of a successor could yield a bump in the party’s popularity. And Mr. Poilievre, who became leader of the Conservatives in 2022, will have to campaign on his own agenda to win over mainstream voters.

“He’d be very different from any other prime minister we’ve had,” said Duane Bratt, a political scientist at Mount Royal University in Calgary, Alberta. “He’s been very combative, and he’s been like that his whole life. That’s great as an opposition leader, and even as a junior minister. But can he do that as prime minister?”

Like other populist leaders, Mr. Poilievre has tapped into the post-pandemic frustrations of voters over rising living costs, unaffordable housing and what to many seemed like a smug Trudeau government that made big decisions — like increasing immigration to historical levels or imposing a carbon tax — without much explanation or consultation.

Three years ago, Mr. Poilievre was one of the few politicians to openly support truckers who paralyzed the center of Ottawa, the capital, for weeks to protest vaccine mandates.

“He’s channeled an anti-elitism in Canada,” said Lori Turnbull, a political scientist at Dalhousie University in Halifax, Nova Scotia. “It is populist, it is anti-institutional. That is a big part of his messaging.”

Mr. Poilievre has pushed a traditionally conservative message of personal freedom, small government, lower taxes, being tough on crime and softer on regulations on Canada’s oil industry.

But he has laced his message with railings against “globalist Davos elites,” threatening to fire Canada’s central banker, embracing cryptocurrency and attacking the mainstream media, especially the public broadcaster, the C.B.C., which he has vowed to defund.

“The problem we’ve had in this country and in all of the countries that have been afflicted by this horrendous utopian wokeism is that it’s been focused on the grand, the grandiosity of the leadership of the egotistical personalities on top and not the things that are grand and great about the common people,” Mr. Poilievre said in a recent interview with Jordan Peterson, the Canadian psychologist and conservative social media star.

“And that is another reason why I think we’re doing very well,” Mr. Poilievre added. “People are saying, finally, there’s someone who’s focused on letting me take back control of my own life.’’

Elon Musk, the billionaire and one of President-elect Donald J. Trump’s most influential supporters, said “great interview” about Mr. Poilievre’s appearance on Mr. Peterson’s podcast. Mr. Musk appeared to embrace Mr. Poilievre even as he continued to belittle Mr. Trudeau.

“Girl, you’re not the governor of Canada anymore, so doesn’t matter what you say,” Mr. Musk posted on social media after Mr. Trudeau said there was not “a snowball’s chance in hell” that Canada would become part of the United States, as Mr. Trump has suggested.

In his personal life, Mr. Poilievre couldn’t be more different from Mr. Trudeau, who — as the son of Pierre Trudeau, who led Canada for nearly 16 years and helped define Canada’s modern identity — grew up in the prime minister’s official residence in Ottawa.

In an apparent effort to emphasize his modest origins, Mr. Poilievre has often told the story of how he was born in Calgary to a 16-year-old mother and given up for adoption. His adoptive parents were schoolteachers who separated when he was 12, after which his father came out as gay.

When he was elected Conservative Party leader in a landslide in 2022, he saluted his biological mother, his adoptive parents and his father’s longtime partner, all of whom were in the audience.

“We’re a complicated and mixed-up bunch, like most families, like our country,” said Mr. Poilievre, who supports same-sex marriage and abortion rights.

Mr. Poilievre has two young children with his wife, Anaida Galindo, a former Senate aide he met in Ottawa. Ms. Poilievre was born in Venezuela but grew up with her family in Montreal. Her husband has often referred to the benefits of immigration by citing as an example Ms. Poilievre’s family, saying they came to Canada “with almost nothing’’ and “like so many immigrant families, built our country.”

Involved in conservative politics in Calgary since his early teens, Mr. Poilievre became the youngest member of Parliament when he was elected in 2004 at the age of 25. He rose quickly through the ranks, impressing older politicians with his hard work, acumen and combativeness, earning the nickname “Skippy.”

He tried to shed the image evoked by the nickname with a makeover in the summer of 2023. Abandoning navy blue suits and ties, he began appearing in public in jeans and sometimes tightfitting T-shirts. He jettisoned his squarish glasses for contacts and aviator sunglasses.

“He’s transformed his own image from this nerdy little guy with the glasses and scowl on his face all the time to this sort of Bitcoin bro who is appealing to young voters, male voters,” said Ms. Turnbull, the political scientist.

Mr. Poilievre said in the interview with Mr. Peterson that he had become “tougher” since becoming Conservative leader and was ready to become prime minister.

“It’s personal for me,” he said. “I don’t come from a privileged or wealthy background. I was adopted by schoolteachers, grew up in a normal suburban neighborhood. We didn’t always have money. But I was able to get here.”