A day after President Trump ordered the suspension of American military assistance, Ukrainian diplomats and politicians scrambled on Tuesday to find a way to salvage their alliance with Washington while the war weary nation prepared for the possibility that it will have to fight on without U.S. support.

With the White House and the Kremlin growing ever more closely aligned, Ukraine was seeking to shore up support from its European allies, many of whom were quick to offer reassurances on Tuesday. Military officials were assessing how long Ukraine’s own stockpiles would last before the situation led to critical gaps on the front.

An emergency meeting in the Ukrainian Parliament was convened on Tuesday to assess the impact of the latest pressure from Trump administration while soldiers in the trenches woke up to the news that an already grueling war could get even more challenging, and brutal.

President Volodymyr Zelensky of Ukraine did not comment directly on the aid suspension — which will affect more than $1 billion in arms and ammunition in the pipeline and on order — but he convened senior civilian and military leaders to discuss “special issues concerning our national resilience.”

“We are working on all possible scenarios to protect Ukraine,” he said in his nightly address to the nation on Monday. “The base line scenario is to hold positions and create conditions for proper diplomacy, for the soonest possible end to this war with a decent peace.”

In comments that seemed aimed at addressing President Trump’s accusations that he doesn’t want peace, Mr. Zelensky added: “We need peace — real, fair peace — not endless war. And we need security guarantees.”

The decision to suspend the delivery of aid came three days after an explosive meeting at the White House in which Mr. Trump berated Mr. Zelensky and called him ungrateful — a rupture in relations that might be difficult to repair.

In the streets and in the halls of Ukraine’s government, there were cries of betrayal. Some Ukrainians passed around clips online of old speeches from previous American presidents vowing to stand by Ukraine, including offering protection in return for its decision to give up nuclear weapons under the Clinton administration.

But more than anger there was a sense of sadness and disbelief.

The first thing that came to mind upon hearing the news was President Franklin D. Roosevelt’s phrase that “this date will go down in infamy,” Oleksandr Merezhko, the chairman of the Foreign Affairs Committee in Parliament, said in an interview. “It was a kind of Pearl Harbor, a political Pearl Harbor, for us.”

It is all the more painful, Mr. Merezhko said, “when it comes not from your enemy, but from whom you consider to be your friend.”

Mykhailo Samus, the deputy director at the Center for Army, Conversion and Disarmament Studies in Ukraine, an independent institution, said a cutoff in aid would mean “that the U.S. is conducting a joint operation with Russia to force Ukraine — the victim of aggression — into surrender.”

“The consequences would be a blow to the U.S.’s position as the former leader of the West,” he added.

The impact to Ukraine would also be severe and grow with time, Mr. Samus said. But “if Trump thinks, or his advisers think, that there is some kind of switch that turns off the Armed Forces of Ukraine,” Mr. Samus added, then the administration has fundamentally misunderstand why Ukrainians are fighting, their will to carry on and the current dynamics on the battlefield.

European leaders — who will convene in Brussels on Thursday to discuss both support for Kyiv and the urgent need for Europe to build up its own military capabilities — were quick to rush to Ukraine’s defense Tuesday morning.

Ursula von der Leyen, who heads the executive arm of the 27-nation European Union, said: “This is Europe’s moment and we must live up to it.”

Appearing in Brussels, she proposed a new program that would make 150 billion euros in loans to member states to fund defense investment.

Britain’s deputy prime minister, Angela Rayner, said America’s suspension of military aid to Ukraine was “a very serious moment.” But she told the BBC that Prime Minister Keir Starmer would continue to work with the U.S., Europe and Ukraine to achieve a lasting peace, and rejected the idea that it would cause a fissure between London and Washington.

Mr. Starmer “won’t choose between the U.S. and Europe,” she said.

The Kremlin, not surprisingly, rejoiced at the latest news.

“If it’s true, then this is a decision which could really push the Kyiv regime to a peace process,” Dmitry S. Peskov, the Kremlin spokesman, told reporters.

“It’s obvious that the United States has been the main supplier of this war,” he added. “If the U.S. stops those supplies, this will be the best contribution to peace, I think.”

However, some Ukrainians and Western military analysts said that rather than speeding the end of the war, the move could give Moscow even more incentive to keep fighting, since Mr. Trump is not applying any pressure on Russia to stop the war. They noted that it was Mr. Putin who started the war and whose army is on the offensive, albeit slowly.

“There is no evidence that Russia would be prepared to accept a deal, and what that would be,” said Malcolm Chalmers, deputy director general of the Royal United Services Institute, a research group in London. “Indeed this decision will encourage Putin to ask for more — including Ukrainian demilitarization and neutrality.”

The pause will halt the delivery of interceptor missiles for Patriot and NASAMS air defense systems, which have saved an untold number of lives as they provide the best shield for Ukrainian cities and critical infrastructure from missile and drone attacks.

While military analysts and Ukrainian officials have said Kyiv is in a better position to sustain its war effort than it was in late 2023, when Congress suspended assistance for months, the move would have cascading effects that will grow with time.

“A U.S. cutoff will eventually have a major impact, especially if European states don’t undertake a crash effort to help Ukraine,” said Professor Phillips O’Brien, an international relations scholar at the University of St. Andrews in Scotland.

A former official in the Biden Administration said Ukraine had enough key munitions to last into the summer because of the surge in deliveries the U.S. made before President Biden left office — shipments that included artillery rounds, rockets and armored vehicles to Ukraine. The official insisted on anonymity to discuss private arrangements.

Mykhailo Podolyak, an adviser to Mr. Zelensky, said the country had weathered suspensions of U.S. military aid in the past and that Ukraine was engaging in a comprehensive audit of it stockpiles, “examining what we have, what can be produced through partnerships, and what can be replaced.”

At the same time, he said, officials in Kyiv were working to restore relations with the Trump administration,

As for the European efforts on Kyiv’s behalf, the Trump administration appeared determined to play down those as well.

Vice President JD Vance warned Ukraine’s allies in Europe that they were only prolonging a losing cause by pledging to support Ukraine.

“Sometimes you will have European heads of state who in public will puff up their chests and say, ‘We’re in it with President Zelensky for the next 10 years’,” Mr. Vance told Fox News Monday night. “And then in private, they will pick up the phone and say, ‘This can’t go on forever. He has to come to the negotiating table’.”

Later, speaking to reporters on Capitol Hill, the vice president encouraged Mr. Zelensky to engage in private discussions to help end the war.

“We need the Ukrainians privately to come to us and say, ‘This is what we need. This is what we want. This is how we are going to participate in the process to end this conflict,’” Mr. Vance said. “That is the most important thing. And that lack of private engagement is what is most concerning to us.”

Despite the increasing tension with the Trump administration, some Ukrainians held out hope that the relationship between Kyiv and Washington could be salvaged.

The Ukrainian parliament issued a statement directed at Mr. Trump, offering effusive praise and gratitude while imploring the administration to not abandon the country as it fights for its survival as an independent nation.

“We are convinced that the security and stable development of our nation are ensured by the unwavering support of the United States and reflect the values that have been the foundation of America’s historic success, inspiring millions of Ukrainians,” the lawmakers wrote.

Ukraine’s prime minister, Denys Shmyhal, said his government would do everything to maintain diplomatic ties with Washington and was prepared to sign an agreement granting America extraordinary access to Ukraine’s natural resources.

“This agreement has been approved by the government of Ukraine,” he said at a news conference. “We are ready to begin this cooperation at any moment.”

Ukraine worked diligently during the Biden administration to maintain bipartisan support in the U.S., hoping that courtship would influence Mr. Trump.

But soldiers and civilians alike have been bracing for this moment.

“Just as we start wearing them down, our weapons supplies get cut off,” said Jr. Lt. Oleh, a soldier fighting around Chasiv Yar in eastern Ukraine. Referring to the U.S., he added: “This has happened before. For some reason, they don’t want to let Russia lose this war.”

Robert Jimison, Liubov Sholudko, Kim Barker, Jeanna Smialek and Stephen Castle contributed reporting.

Claudia Sheinbaum, the president of Mexico, stood underneath a giant Mexican flag and before troops at a military installation in Mexico City. It was Flag Day last month and she used her speech as an opportunity to, figuratively and literally, rally around it.

“Mexico must be respected,” she said, adding later: “Its people are brave. We know that when our people unite around their history, their country and their flag, there is no force in the world that can break their spirit.”

Times had changed, she said: Mexico would not bow down to foreign governments.

Given the circumstances — President Trump’s steep tariffs against Mexico went into effect in the first minutes of Tuesday — Ms. Sheinbaum’s optics were fitting. As Mr. Trump once again targeted Mexico, using the hammer of tariffs as a negotiating tool, a sense of Mexican nationalism has been strengthened.

The Mexican government and businesses have rekindled a “Made in Mexico” campaign. Some Mexicans have called for boycotts of U.S. companies and products, while others have put together lists of Mexican stores and brands to support instead of American ones.

Ms. Sheinbaum is frequently featured on the front page of local newspapers with members of the country’s military or in front of a giant Mexican flag. Private companies have taken out nationalistic advertisements, one featuring the president leading the masses and carrying a banner saying, “Mexico united, never defeated!”

And Ms. Sheinbaum, who has been trying to balance a pro-Mexico drumbeat while advocating cooperative dialogue with American officials, has seen her approval ratings rise as high as 80 percent, according to one poll. She has not only succeeded a popular president, Andres Manuel López Obrador, who reshaped Mexican politics and was her mentor, but has come into her own at a time of global upheaval under Mr. Trump.

“There’s a lot of support for the president now,” said Juan Manuel Sánchez, 57, an artisan in Mexico City who also praised Ms. Sheinbaum’s crackdown on drug trafficking.

During his first term, Mr. Trump used tariffs to renegotiate the North American Free Trade Agreement and strike a new U.S.-Mexico-Canada agreement, which he signed in 2020. He has used similar tactics now against Mexico and Canada, while arguing that too many illegal drugs and migrants are flowing from the two countries into the United States.

A month ago, Mr. Trump signed an executive order calling for 25 percent tariffs on Mexican imports. But less than a day before they were to go into effect, Mr. Trump and Ms. Sheinbaum spoke on the phone and announced an agreement to delay them for 30 days.

Under the terms of that deal, Mexico posted an additional 10,000 Mexican National Guard troops on the border to help stem the flow of fentanyl and migrants into the United States. In return, Ms. Sheinbaum said, the U.S. government would work to stop the flow of guns into Mexico.

Even though the number of migrant crossings at the southern border has dropped to once unthinkable levels since Mr. Trump took office in January, Mexican officials were significantly deterring migration to the United States months before. Last week, Mexico sent nearly 30 top cartel operatives wanted by American authorities to the United States, one of the largest such handovers in the history of the drug war.

“There’s a lot of unity in the country in the face of what is happening,” including Mr. Trump’s economic threats, Ms. Sheinbaum said on Monday, hours before the tariffs took effect.

Although Mr. Trump insisted on Monday that the tariffs would begin the next day, the cloud over Mexico from the north has loomed since his most recent presidential campaign. It led to uncertainty and frustration but also boosted national pride.

Agustin Barrios Gómez, a former Mexican congressman and a founding member of the nonprofit Mexican Council on Foreign Relations, said that even Mexicans who didn’t vote for Ms. Sheinbaum “understand that right now, Mexico’s national interest — beyond party politics — is to rally around our president.”

One reason for the surge in support for her, Mr. Barrios Gómez said, was to ensure Ms. Sheinbaum has enough political capital within the country to be in a stronger negotiating position with Mr. Trump come what may.

Nationalism is complicated in Mexico, Mr. Barrios Gómez said, because it is so intricately intertwined with the United States geographically, culturally and economically, as well as with immigration and security.

“We are not neighbors, we’re roommates,” he said. In other words, analysts said, the U.S. tariffs against Mexico will hurt both economies, as would the reciprocal tariffs suggested by Ms. Sheinbaum. (Mr. Trump is also threatening separate 25 percent tariffs on global steel and aluminum imports, which would affect Mexico.)

For Mexico, the tipping point against the United States has not been reached, Mr. Barrios Gómez said late last week before the tariffs went into effect, but “if you call someone your enemy enough, you might just turn them into one.”

The specter of a trade war between the countries has changed the perception in Mexico of Mr. Trump and of its relationship with the United States.

According to the Mexican polling firm Buendía & Marquéz, the number of respondents in Mexico who believed the relationship between Ms. Sheinbaum and Mr. Trump was at least good dropped significantly between last November and February, while the number of respondents who have a negative opinion of Mr. Trump jumped to 80 percent in mid-February from 66 percent in early January.

Mr. Trump has nevertheless praised Ms. Sheinbaum as a “marvelous woman” while mocking Canada’s prime minister, Justin Trudeau. Mr. Trudeau, who has become increasingly unpopular at home, is entering his final days in office while Ms. Sheinbaum’s popular foundation is stronger. She resoundingly won election last summer and began her six-year term in October.

During her Monday morning news conference, Ms. Sheinbaum once again called for calm ahead of Mr. Trump’s tariffs deadline and said she hoped to strike a last-minute deal, which did not materialize. “Obviously we don’t want there to be tariffs,” she said, adding that her government would respond.

Since before Mr. Trump’s inauguration, her administration has been promoting what it calls “Plan Mexico,” a strategy meant to diversify its economy to make it less dependent on the United States, to reinvigorate Mexican manufacturing and propel the country to become one of the world’s top 10 economies. (It is currently the 15th largest, according to the International Monetary Fund.)

As part of that effort, Ms. Sheinbaum’s administration started the “Made in Mexico” drive, in which an official seal is placed on products made in the country that meet certain requirements. The seal, with an illustration of a Mexican eagle, was created in 1978 to promote Mexican goods and has been revived by presidents over the years.

As the threatened U.S. tariffs were paused a month ago, Mexico’s secretary of economy, Marcelo Ebrard, told companies that the government wanted to once again push the “Made in Mexico” seal.

Last week, Walmart Mexico, the largest private employer in the country with 200,000 workers, unveiled its efforts to put the “Made in Mexico” seal — with the added word “proudly” — in the aisles of its 3,000 stores throughout the country. Although Walmart is an American brand, Javier Treviño, Walmart Mexico’s senior vice president of corporate affairs, said the company wanted to show customers that it is a Mexican entity and that most of the products it sells are made within the nation.

The campaign “is very important for us because we have to strengthen investment and confidence in Mexico and ensure that the economy can grow, because the environment is not easy,” Mr. Treviño, a former Mexican congressman, said in an interview.

Other big companies have joined Ms. Sheinbaum’s push, including Grupo Modelo, the brewing giant that makes Corona and Modelo beers, which announced it would put new “Made in Mexico” caps on bottles.

On Saturday, Mr. Sánchez, the Mexico City artisan, was at his neighborhood market, which, he said, proved that he prefers to shop locally. Before Mr. Trump’s tariffs went into effect, he said he might consider boycotting U.S. companies and products if they did.

Unlike in Canada, where locals have been shunning American products and buying more Canadian flags since Mr. Trump threatened the tariffs, Mr. Sánchez said that Mexicans were already nationalistic and that most had a flag.

“But when something very serious happens here,” he said, “we all unite.”

Maria Abi-Habib contributed reporting from Mexico City.

Arab leaders convened for an emergency summit in Cairo on Tuesday, facing pressure to come up with something that has proved elusive for decades: a comprehensive Arab vision for Gaza, just as the Israel-Hamas cease-fire is teetering and Israel, buoyed by President Trump’s backing, holds the upper hand.

“Arab Summit: Rescue mission,” read a stark headline on Saturday in Al Ahram, Egypt’s state-owned flagship newspaper, over an article outlining the “uphill task” facing Arab leaders.

The delegates were expected to ratify an Egyptian proposal that would involve spending $53 billion to rebuild Gaza without, as Mr. Trump has suggested, moving Palestinians out of the strip, according to a preliminary draft of the proposal, which was shared with The New York Times by an Arab diplomat.

The proposal also calls for putting a committee of technocrats and other figures unaffiliated with Hamas in charge of the territory for an initial six-month period. The Egyptian government did not respond to a request for comment, but the editor in chief of Al Ahram Weekly, a state-owned media outlet, confirmed the document’s authenticity.

The Arab summit was called in response to Mr. Trump’s proposal last month to expel Palestinians from Gaza, send them to Egypt and Jordan and turn the territory into a tourism hub — an idea that much of the world has rejected as tantamount to ethnic cleansing.

Egypt, Jordan and other Arab allies of the United States have pushed back hard on the plan, saying it would destroy any remaining hope of a Palestinian state and destabilize the entire region.

Mr. Trump appeared to soften his position recently, saying that he was “not forcing” his Gaza idea on anyone. But the Arab world remains deeply concerned. Adding to those worries is the uncertainty surrounding the cease-fire in Gaza, which has paused the bloodshed there for six weeks and seen Israel and Hamas exchange Palestinian prisoners for Israeli hostages.

In the latest crisis to shake the agreement, Israel began blocking all aid and goods from entering Gaza on Sunday, attempting to strong-arm Hamas into extending the first phase of the truce, which just expired, and swapping more prisoners for hostages without moving toward a permanent end to the war.

Israel also recently drove tens of thousands of Palestinians from their homes in the Israeli-occupied West Bank and ruled out allowing them to return, intensifying Arab fears that an Israel emboldened by Mr. Trump’s support will attempt to annex the West Bank. Israel says it is responding to a rising threat of militancy from the West Bank. The Israeli military denies any forced evacuations, but has said it ordered people to leave buildings close to what it said were militant hide-outs.

The Israeli-Palestinian conflict has plagued the Middle East for decades. But recent events have brought the question of how to resolve it to a head, forcing Arab countries to scramble over the last few weeks to come up with a counterproposal to Mr. Trump’s.

Beyond insisting on Palestinian statehood and rejecting forcible displacement, Arab countries have not yet agreed on an alternative vision for Gaza — let alone one that Palestinian political factions, Israel, the United States and other countries would sign on to.

Many major questions remain, such as how to govern Gaza, how to manage its security, how to rebuild it and how to sideline Hamas, which remains the most powerful force in the enclave.

And any plan would have to get around a more fundamental issue: While Arab leaders will support only a framework that would include at least a nominal path toward Palestinian statehood, Israeli leaders are against embarking on a path that would lead to Palestinian sovereignty.

The leaders of Egypt, Jordan and Gulf Arab states met last month in Riyadh, Saudi Arabia, to strategize ahead of Tuesday’s summit in Cairo, which will include all 22 members of the Arab League as well as the United Nations secretary general and the European Council’s president.

But the leaders of two of the most powerful Gulf nations — Saudi Arabia and the United Arab Emirates — did not show for the Cairo summit, raising questions about whether there is unified Arab support for Egypt’s plan.

According to the draft proposal expected to be discussed on Tuesday, the transitional governing committee would pave the way for the Palestinian Authority, the internationally recognized body that administers parts of the West Bank, to “fully return” to Gaza. The authority administered Gaza until Hamas, which had won parliamentary elections in 2006, seized control of the strip by force in 2007.

Gaza and the West Bank should be united as one state, Arab officials argue, and must be linked in any conversations about Gaza. The Palestinian Authority president, Mahmoud Abbas, has so far appeared reluctant to give his blessing to any governing arrangement that does not put him fully in control of Gaza.

One open question concerns who will manage Gaza’s security after the war permanently ends. Egypt is proposing an international force be deployed in Gaza and the West Bank, according to the draft, which does not specify which countries might supply troops to such a force.

Hamas officials have said they would be willing to hand over control of civilian affairs to a governing committee of which the group was not a part, as long as Gaza’s postwar future was determined by Palestinian “national consensus,” according to a statement from the group on Tuesday.

But they refuse to demilitarize in Gaza, a crucial demand of both Israel and Mr. Trump. The American president’s top Middle East envoy, Steve Witkoff, said in an interview with CBS’s “Face the Nation” last month that Hamas “has to go.” An official media outlet belonging to Hamas said on Tuesday that “the resistance’s weapons are a red line.”

The Egyptian proposal acknowledges that it will be difficult to disarm Palestinian groups in Gaza. But the draft suggests that the armed Palestinian resistance will only disappear once the Palestinians secure statehood and rights, saying the issue can be resolved “if its causes are removed through a clear horizon and a credible political process that ensures the legitimate rights of Palestinians.”

The Egyptian proposal is most detailed when it comes to Gaza’s reconstruction. Palestinians in Gaza would stay in temporary housing units made of shipping containers on seven sites throughout the territory, with an average of six people living in each. In the first phase, which would last six months and cost $3 billion, rubble and unexploded ordnance would be cleared, 1.2 million people would be moved into prefabricated temporary housing units and 60,000 partially destroyed housing units would start to be rehabilitated.

In the next phase, which Egypt estimates would cost $20 billion and last until 2027, utilities and permanent housing would be rebuilt, and rubble would be used to expand Gaza’s surface area into the sea. Industrial zones, a fishing port, a seaport and an airport would be built during a final phase costing $30 billion and lasting until 2030, according to the draft.

Under this framework, oil-rich Gulf nations would likely pay for Gaza’s reconstruction, though Egyptian officials have also suggested Europe could also contribute funds. The draft says that Egypt will convene a donor conference to drum up funding and investments “as soon as possible.”

Egypt’s foreign minister, Badr Abdelatty, said in a news conference on Saturday with the Palestinian prime minister and foreign minister that Egypt had volunteered to train Palestinian police forces to be deployed in Gaza while the territory is rebuilt.

Jordan is also training Palestinian police personnel, according to the Egyptian draft proposal, which said other countries could possibly join that effort.

Natan Odenheimer and Aaron Boxerman contributed reporting from Jerusalem, and Rania Khaled from Cairo.

As the United States and Europe condemned Russia for its invasion of Ukraine, Sasa Bozic responded by opening the Putin Café in the Bosnian city of Banja Luka, decorating it with a mannequin of the Russian president — a foot taller than Vladimir V. Putin is in real life.

Today, with much of Europe horrified at President Trump’s attack on President Volodymyr Zelensky of Ukraine in the Oval Office, Mr. Bozic has a new project: a motel and restaurant complex called “Trump and Putin’s Place.” He plans to open it this summer.

Paying tribute to Mr. Trump and Mr. Putin, Mr. Bozic said, is not political — just “a “marketing trick” that works in Banja Luka. Since the 1989 collapse of Communism in Eastern Europe, many in the mostly ethnic Serb city and surrounding region have looked favorably on Russia and with hostility on an American-led order in Europe that Mr. Trump appears intent on upending.

A Biden Café, Mr. Bozic said, would never work, even less an eatery named after President Zelensky, but “everyone here likes Putin and Trump.”

Banja Luka is the capital of Republika Srpska, a Serb-controlled region of Bosnia and Herzegovina that was born from the ethnic cleansing of the Balkan wars of the early 1990s. That violence more than three decades ago punctured hopes that the demise of Communism would open a new era of prosperity and harmony. It gave an early foretaste of the appeal and destructive power of ethnonationalism, a force now resurgent around the world.

The Serb region has for decades felt out of step with — and victimized by — what it views as a hostile, American-dominated world order committed, at least in principle, to human rights, democracy and territorial integrity.

Many ethnic Serbs have regarded Russia, which shares their Orthodox Christian faith, as a protector against the West, which intervened militarily during the 1992-95 war to help Bosnia’s Muslim populations and again in 1998 to break Serbia’s grip on Kosovo.

Serbs inside Serbia and beyond its borders in Bosnia still harbor bitter memories of NATO bombings in the 1990s.

Now many feel that things have changed with the return of President Trump.

“Trump’s America is different,” said Mladen Ivanic, a former prime minister of Bosnia’s Serb enclave. While opposed to the region’s ethnonationalist leadership, he hopes the new administration in Washington will be more sympathetic to Serb concerns. But he also sees tumult ahead.

“We are now living in a new world where everything is possible, even conflict between America and Europe,” Mr. Ivanic said. “I never thought that was possible.” He added that he believed that “Trump has no interest in the Balkans,” but his demolition of longstanding assumptions about what the United States stands for has “changed everything.”

The change has dismayed former Communist countries that, thankful for Washington’s hostility to Moscow during the Cold War, count themselves as loyal American allies.

Vytautas Landsbergis, a former leader of Lithuania who led his Baltic nation, then still a Soviet republic, to declare independence in 1990, described Mr. Trump’s confrontation with Mr. Zelensky as a crude betrayal.

“They invited a guest, beat him up, spat on him, and threw him out the door,” Mr. Landsbergis said. “What happened in Washington is an extremely low level” that “has never been seen before.”

Lech Walesa, the former Solidarity trade union leader in Poland and a global symbol of resistance to tyranny, on Monday joined former political prisoners to send a letter to President Trump voicing “horror and disgust” at his hectoring of President Zelensky, saying it reminded them of their encounters with imperious Communist-era officials.

For those who see the United States as a bully rather than a liberator, the prospect of Washington turning its back on old verities has been met with glee.

Milorad Dodik, the Republika Srpska’s embattled leader, has been fishing eagerly in the troubled waters stirred up by President Trump. He praised the Oval Office confrontation with Mr. Zelensky, who had been trying to correct Mr. Trump’s depictions of the origins of the war in Ukraine, as a triumph for “truth” over “fairy tales.”

Hoping that Washington will rally to his side against Bosnia’s central government in Sarajevo, Mr. Dodik recently hosted a visit to Banja Luka by Rudolph W. Giuliani, the former New York mayor and Mr. Trump’s former attorney. Mr. Giuliani arrived shortly before a Bosnian court convicted Mr. Dodik of flouting the rulings of an international official overseeing implementation of the 1995 Dayton peace agreement.

That agreement, brokered by the Clinton administration, put an end to more than three years of ethnic conflict in Bosnia and has kept the peace since.

Mr. Dodik, who has long embraced Russia as his protector, is now looking to Washington for help. In a letter to Mr. Giuliani, he wrote: “You and President Trump understand better than anyone the ruthless nature of the deep state and the lengths they go in attacking political opponents.”

The visit did not go entirely as planned. Mr. Giuliani obligingly portrayed Bosnia and Herzegovina, a country from which Mr. Dodik has repeatedly threatened to secede, as a menacing hotbed of Islamic extremism and wore a MAGA-style hat with the words “Make Srpska Great Again.” But he inadvertently insulted his host by calling him a “Bosnian,” a label that Mr. Dodik uses for Muslims.

A day after Mr. Giuliani attended a rally of Mr. Dodik’s ethnic Serb supporters, the enclave’s leader was sentenced in absentia last week by the Sarajevo court to a year in prison and barred from holding public office for six years. He says he does not recognize the court’s authority.

Mr. Dodik’s outreach to Washington, said Damir Kapidzic, a professor of politics at the University of Sarajevo, has been motivated by his desire to stay out of prison and get U.S. sanctions against him lifted.

“He has his back against the wall,” he said, adding: “He hopes the uncertainty that Trump has thrown into the world will help him.”

Mr. Kapidzic said this uncertainty bodes ill for a shaky American-backed order in the Balkans whose stability depends on U.S. cooperation with European countries.

A return to war, he said, was highly improbable — too many young people of fighting age have moved abroad and there are no large stocks of weapons, as there were when Yugoslavia fell apart.

But, Mr. Kapidzic said, Bosnia risks a destabilizing scramble for influence between outside powers, including Russia, China and Turkey, “if the Trump administration decides to completely pull back from supporting the multilateralism that ended the Balkan wars.”

Aleksandar Trifunovic, the editor in chief of Buka, a news site in Banja Luka, agreed that a return to the violence of the 1990s was unlikely, though there have been threats against the judge who ruled against Mr. Dodik.

More worrying, he said, was an unraveling of the norms that have kept Bosnia together as a state, albeit a highly dysfunctional one. Mr. Dodik last week vowed to purge “traitors” — ethnic Serbs who worked in his region for the police and other institutions under the control of the central government in Sarajevo.

“We will hang their names on plaques wherever we can, in the media and everywhere,” he said. “We will not tolerate betrayal.”

Mr. Trifunovic said that Mr. Dodik has been emboldened by President Trump’s campaign against the “deep state,” particularly the dismantling of U.S.A.I.D. and Elon Musk’s denunciation of the aid agency — without substantiation — as a “criminal organization.”

“It is very dangerous,” Mr. Trifunovic said, adding that he had never received grants from U.S.A.I.D. but had still been accused by Mr. Dodik as being part of a group of “criminals” using American money “to destroy the Republika Srpska and Milorad Dodik.”

Drasko Stanivukovic, the opposition mayor of Banja Luka, said he disagreed with Mr. Dodik on many things but shared his hope that President Trump would help ethnic Serbs protect their identity and territory. “We are all cheering for Trump here,” he said. “The world has been ruled by liberal values for too long.”

Tanja Topic, a Banja Luka political commentator for a Serbian magazine, said the increasingly aggressive mood reminded her of the 1990s.

“There are the same poisonous narratives, the same people but thankfully no guns this time,” she said. Politicians like Mr. Dodik, she added, “don’t like rules and have put a big bet on Trump.”

In the weeks since President Trump signed an executive order dismantling the U.S. Agency for International Development, Andrea Minaj Casablanca’s phone has been inundated with desperate pleas for help.

A counselor who works with nonprofits catering to members of Uganda’s embattled L.G.B.T.Q. population, she has fielded urgent requests from people seeking H.I.V. medications, therapy sessions and shelter in the wake of Mr. Trump’s executive order. Ms. Casablanca responded to these calls while grappling with her own crisis: being fired from a job that was funded by U.S.A.I.D.

“Our whole world has been turned upside down,” Ms. Casablanca, a 25-year-old transgender woman, said on a recent afternoon in Kampala, the capital. “Everyone is in fear of the future.”

L.G.B.T.Q. people in Uganda have in recent years endured an intensifying crackdown in this conservative East African nation. President Yoweri Museveni signed a law in 2023 that calls for life imprisonment for anyone who engages in same-sex relations in Uganda and up to a decade in prison for anyone who tries to.

Now, activists say, the U.S.A.I.D. cuts have put them at even greater risk, with shelters underfunded, hundreds of individuals unemployed and many more facing discrimination and violence. Vital medical supplies remain scarce, while members of L.G.B.T.Q. groups increasingly report feeling depressed or suicidal.

The law also allows for the death penalty for anyone convicted of “aggravated homosexuality,” a sweeping term defined as acts of same-sex relations with minors or disabled people. Mr. Museveni and his government have claimed that homosexuality is a Western phenomenon and that the law protects children and defends the sanctity of the family.

“This is a reckoning,” said Richard Lusimbo, the founder and director general of the Uganda Key Populations Consortium, a nonprofit promoting L.G.B.T.Q. rights and health.

“With these programs gone, I worry our communities will be pushed back into disarray and disempowerment,” he added. “It’s heartbreaking.”

Muhoozi Kainerugaba, Mr. Museveni’s son and the chief of the Ugandan military, urged President Trump to restore aid for those infected with H.I.V., adding, “Our people will be grateful.”

The United States provides more than $970 million annually in development as well as humanitarian and security assistance to Uganda. In 2023, about $440 million was spent on health programs, followed by emergency relief, agriculture and education services, according to U.S. government data.

For years, the United States supported L.G.B.T.Q. groups in Uganda through U.S.A.I.D.-funded initiatives, offering H.I.V. treatment, legal training and resources for activism. Previous U.S. governments also condemned human rights violations against gay Ugandans, imposing trade and travel restrictions in response.

Just days after Mr. Trump took office in January, his administration announced it was halting all foreign aid as it conducted a 90-day audit of spending. Secretary of State Marco Rubio issued a waiver to continue funding lifesaving medicines and medical services, including for H.I.V. and tuberculosis care and treatment.

But the exemption excluded programs that promoted diversity, equity and inclusion. That meant L.G.B.T.Q. people were unable to receive medication to protect them from H.I.V. infections. Several Ugandan gay rights groups said that, during the audit, they were informed that their projects were permanently terminated because they promoted diversity, equity and inclusion.

In late February, the Trump administration announced it had completed a review of all U.S. foreign aid and was cutting 90 percent of U.S.A.I.D. programs, including those providing lifesaving medication.

The rapid loss of aid from the United States has left many gay Ugandans terrified. “It’s like running from one fire to another fire,” said Agy Hrd, the executive director of Africa Queer Network, which works on L.G.B.T.Q. rights in over a dozen African countries.

Ms. Hrd, who has vigorously campaigned against the anti-homosexuality law in Uganda, said she was attacked and beaten in the country last year. With the sudden funding cuts, she worries that many gay people, especially in rural areas, will get sick or encounter violence and have nowhere to turn for safety or support.

“I haven’t slept well in weeks,” she said. “We have a big battle ahead of us.”

An informal survey of 127 nonprofits dealing with L.G.B.T.Q. issues and other at-risk groups carried out by Uganda Key Populations Consortium, Mr. Lusimbo’s organization, showed that 97 percent of them had lost almost all their budgets as a result of the U.S.A.I.D. cuts. Mr. Lusimbo said he had to let most of his staff go in the past month.

Organizations have begun distributing what few resources they have left, and relying on volunteers to maintain essential services, like finding shelters or delivering testing kits. Brant Luswata, the executive director of Icebreakers Uganda, a gay rights organization, said that as services were eliminated, his group had been asked to return filing cabinets and chairs purchased with American tax dollars.

Activists said some L.G.B.T.Q. clinics were now charging for services that had previously been free, like H.I.V. testing. Mental health services have been reduced or cut altogether, they said. There are also fears that the abrupt suspension of aid will undo years of progress in teaching Ugandans about safe sex or expose people living with H.I.V. to life-threatening infections because of their weakened immunity.

“The infections have not gone on a pause just because there’s a 90-day review,” Mr. Lusimbo said. “We live in a global village,” he added. “Everyone’s health is in jeopardy.”

The conditions for L.G.B.T.Q. Ugandans are so perilous that shelters often move locations frequently or relocate individuals in order to avoid personal attacks or raids from the authorities. Now, some of those shelters are beginning to close.

Since 2020, approximately three dozen shelters in secret locations across Uganda have protected thousands of gay people from homelessness and violence, according to John Grace, the coordinator of the Uganda Minority Shelters Consortium.

The shelters relied on intermediaries who received American funding, including from U.S.A.I.D. and the Centers for Disease Control and Prevention. But because of gradual funding cuts and policy changes under the Trump administration, at least a dozen shelters have now closed, said Mx. Grace, who is nonbinary.

Those that remain are understaffed and overcrowded and have begun turning people away, they said.

“It’s a total mess,” said Mx. Grace, 32, whose family kicked them out after they came out as nonbinary a few years ago. “These shelters are a lifeline for so many people, and now they’re struggling to survive.”

For Ms. Casablanca, the counselor, the relentless stream of phone calls shows no sign of letting up. Despite not receiving her $40 monthly paycheck funded by U.S.A.I.D., she has chosen to continue working as a volunteer.

Across Kampala and other Ugandan cities, she said, L.G.B.T.Q. people are reaching out, worried about where to get medication, condoms, lubricants and tests. Some call in tears, sharing their struggles with fear and isolation, she said. Many, like her, also worry about where their next paycheck will come from or how they will pay rent.

To make ends meet, she said, she has taken on work as a party decorator. “We need to survive in this darkness,” she said.

The Trump administration’s decision to temporarily suspend the delivery of all military assistance to Ukraine sent shock waves through Europe on Tuesday, even as details about the move remained scant.

The decision — which affects more than $1 billion in arms and ammunition in the pipeline and on order — made real a fear that has racked Ukraine since President Trump’s re-election.

Here’s what to know.

Why is the U.S. suspending aid?

In the run-up to Mr. Trump’s inauguration, the Biden administration rushed to deliver as much support to Ukraine as it could out of concern that Mr. Trump would cut military assistance. And President Volodymyr Zelensky of Ukraine has been working furiously to shore up European support.

Mr. Trump’s overtures toward Russia since he took office aggravated those fears — culminating with an explosive confrontation in the Oval Office on Friday between the U.S. leader and Mr. Zelensky. Mr. Trump castigated the Ukrainian president for not being grateful enough for U.S. support in the war with Russia.

The decision to suspend aid came out of meetings at the White House on Monday between Mr. Trump and his senior national security aides, according to senior administration and military officials, who spoke on the condition of anonymity to discuss internal deliberations. It appears aimed at forcing Mr. Zelensky to agree to a cease-fire on terms Mr. Trump dictates, or condemns the country to larger battlefield losses.

The officials said the directive would be in effect until Mr. Trump determined that Ukraine had demonstrated a good-faith commitment to peace negotiations with Russia. It was not immediately clear what that might look like or how long the suspension will last. For now, it will be up to Kyiv and its European allies to try to keep Ukraine’s guns firing.

Has this ever happened before?

Mr. Trump’s move has few direct precedents in recent American history. The United States has paused the transfer of specific weapons systems to allies and partners, like when President Joseph R. Biden Jr. suspended deliveries of 2,000-pound bombs to Israel that he feared could be used against civilians in Gaza. But a full cutoff is unusual, and is essentially an ultimatum.

It is not the first time Mr. Trump has blocked aid to Ukraine. During his first term, he pushed Mr. Zelensky to help tarnish Mr. Biden when he was the leading Democratic candidate for president. He withheld military aid to Ukraine at the same time — releasing it only after pressure from advisers and Republican senators. Revelations about those actions led to Mr. Trump’s first impeachment.

How much aid has Ukraine received from the U.S.?

Ukraine has depended on a lifeline of arms from the United States since the day after Russian troops crossed the border in February 2022, when the Biden administration authorized $350 million worth of arms from the Defense Department’s stockpiles for Ukraine.

The Pentagon went on to send 71 more shipments of military aid from existing stockpiles worth $33.8 billion.

The United States has also provided $33.2 billion under a program called the Ukraine Security Assistance Initiative, which provides funds that Kyiv can only use to buy new military hardware directly from U.S. defense companies.

In total, the United States has spent about $119 billion on the war in Ukraine, with $67 billion of that going to military spending, according to one frequently used tracker. Europe has dedicated about $138 billion to Ukraine, of which about $65 billion has been in military aid.

Mr. Trump has vastly overstated the amount of aid the United States has given Ukraine.

According to the Pentagon, about $3.85 billion remains of what Congress authorized for additional withdrawals from the Defense Department’s stockpile for Ukraine.

What’s at stake?

Ukraine relies on the United States for Patriot air-defense missiles, which are the only system capable of intercepting Russian ballistic missiles, such as the Kinzhal hypersonic missiles that have been fired at Kyiv.

It also has received advanced weapons, including surface-to-surface ballistic missiles, along with more than three million 155-millimeter artillery shells, tens of thousands of guided artillery rockets and antitank missiles, thousands of antiaircraft missiles and armored vehicles and dozens of tanks. The United States also provides Ukraine with parts, maintenance and technical support.

What will the impact be?

Mr. Zelensky has said that losing U.S. military assistance would be a devastating blow but that Ukrainian forces would keep fighting.

European leaders have pledged their unwavering support and further aid for Ukraine. And Ukraine’s reliance on American ammunition, howitzers and armored vehicles has lessened as its own arms production has ramped up and exploding drones, also made domestically, have surpassed other weapons in lethality.

Through its own weapons production and arms deliveries from Europe, Ukraine could withstand a U.S. shutdown for some weeks or even a few months, U.S. officials and analysts said on Monday.

“The reality is that Ukraine is far less dependent on the United States for its day-to-day combat needs than it was a year ago,” said Michael Kofman, a senior fellow at the Carnegie Endowment for International Peace, who has visited Ukraine several times since the war started three years ago.

When U.S. military aid stopped flowing last year for several months, the protection provided by Patriot air defense batteries frayed and Russian missiles pounded Ukraine’s energy infrastructure. It took longer for the impact to be felt on the front lines, where Ukrainian commanders said they were forced to ration ammunition as supplies dwindled.

Reporting was contributed by Andrew E. Kramer, Marc Santora, Erica L. Green, Eric Schmitt, David E. Sanger and Julian E. Barnes.