Outside the Zadna Bakery in central Gaza one recent afternoon, the long lines of people waiting for bread were threatening to dissolve into chaos at any minute.

A security guard shouted at the crowds that pushed toward the bakery door to wait their turn. But no one was listening.

Just a few steps away, scalpers were hawking loaves they had gotten earlier that day for three times the original price. The sunset meal that breaks Muslims’ daylong fast during the holy month of Ramadan was approaching and across Gaza, bread, water, cooking gas and other basics were hard to come by — once again.

Lines had not been this desperate, nor markets this empty, since before the Israel-Hamas cease-fire took hold on Jan. 19. The truce had allowed aid to surge into Gaza for the first time after 15 months of conflict during which residents received only a trickle of supplies.

But no aid has gotten in since March 2. That was the day Israel blocked all goods in a bid to pressure Hamas into accepting an extension of the current cease-fire stage and releasing more hostages sooner, instead of moving to the next phase, which would involve more challenging negotiations to permanently end to the war.

Now, the aid cutoff, exacerbated by panic buying and unscrupulous traders who gouge prices, is driving prices to levels that few can afford. Shortages of fresh vegetables and fruit and rising prices are forcing people to once again fall back on canned food such as beans.

Though the canned food provides calories, experts say, people — and children in particular — need a diverse diet that includes fresh foods to stave off malnutrition.

For the first six weeks of the cease-fire, aid workers and traders delivered food for Gazans, many still weak from months of malnutrition. Medical supplies for bombed-out hospitals, plastic pipes to restore water supplies and fuel to power everything also began to flow in.

Data from aid groups and the United Nations showed that children, pregnant women and breastfeeding mothers were eating better. And more centers started offering treatment for malnutrition, the United Nations said.

These were only small steps toward relieving the devastation wrought by the war, which destroyed more than half of Gaza’s buildings and put many of its two million residents at risk of famine.

Even with the sharp increase in aid after the truce began, Gaza health officials reported that at least six newborn babies had died from hypothermia in February for lack of warm clothes, blankets, shelter or medical care, a figure cited by the United Nations. The reports could not be independently verified.

Most hospitals remain only partly operational, if at all.

Aid groups, the United Nations and several Western governments have urged Israel to allow shipments to resume, criticizing its use of humanitarian relief as a bargaining chip in negotiations and, in some cases, saying that the cutoff violates international law.

Instead, Israel is turning up the pressure.

Last Sunday, it severed electricity supplies to the territory — a move that shuttered most operations at a water desalination plant and deprived about 600,000 people in central Gaza of clean drinking water, according to the United Nations.

The Israeli energy minister has hinted that a water cutoff might be next. Some wells are still functioning in central Gaza, aid officials say, but they supply only brackish water, which poses long-term health risks to those who drink it.

Israel had already closed off all other sources of electricity that it used to provide for Gaza, a measure that followed the Oct. 7, 2023, Hamas-led attack on Israel that began the war. That left essential services to run on solar panels or generators, if power was available at all.

Now there is no fuel coming in for anything, including generators, ambulances or cars.

Israel argues that about 25,000 truckloads of aid that Gaza has received in recent weeks have given people sufficient food.

“There is no shortage of essential products in the strip whatsoever,” the Foreign Ministry said last week. It repeated assertions that Hamas is taking over the aid entering Gaza and that half the group’s budget in Gaza comes from exploiting aid trucks.

Hamas has called the aid and electricity cutoffs “cheap and unacceptable blackmail.”

Gaza residents say that, for the moment, at least, they do have food, though often not enough.

But supplies that humanitarian groups amassed in the first six weeks of the cease-fire are already dwindling, aid officials warn. That has already forced six bakeries in Gaza to close and aid groups and community kitchens to reduce the food rations they hand out.

The order to block aid also cut off Gaza’s access to commercial goods imported by traders.

In the city of Deir al-Balah in central Gaza, a street market was quiet this week as the vendors’ stocks of fruits, vegetables, oil, sugar and flour ran low. Vegetable sellers said the price of onions and carrots had doubled, zucchini had nearly quadrupled and lemons cost nearly 10 times as much. Eggplants were hard to find and potatoes impossible.

As a result, the sellers said, the few customers who still came bought only a couple of vegetables, not by the kilogram as many once did. Others had not had the means to buy anything for months.

Many Gazans lost their jobs and spent their savings to survive the war. When prices skyrocketed, they were left almost completely reliant on aid.

Yasmin al-Attar, 38, and her husband, a driver, wandered from stall to stall in the Deir al-Balah market, looking for the cheapest prices on a recent day. They have seven children, a disabled sister and two aging parents to support.

It had been hard enough to afford the bare minimum of ingredients for iftar, the meal that breaks the daily fast during Ramadan, Ms. al-Attar said. But with fuel blocked, it was also getting tough to find fuel for her husband’s car and for cooking.

“Just three days ago, I felt a little relief because prices seemed reasonable,” she said. Now, the same money would only be enough for a much smaller quantity of vegetables.

“How can this possibly be enough for my big family?” she said.

That night, she said, they would probably make do with lentil soup, with no vegetables. And after that? Maybe more canned food.

Stall owners and shoppers alike blamed large-scale traders for the shortages, at least in part, saying they were hoarding supplies to push up prices and maximize their profits. Any vegetables available at reasonable prices were being snapped up and resold for much more, said Eissa Fayyad, 32, a vegetable seller in Deir al-Balah.

It did not help that people rushed out to buy more than they needed as soon as they heard about the Israeli decision to blockade aid again, said Khalil Reziq, 38, a police officer in the city of Khan Younis in central Gaza whose division oversees markets and shops.

Hamas police officers have warned businesses against price-gouging, vendors and shoppers said. In some cases, Mr. Reziq said, his unit had confiscated vendors’ goods and sold them for cheaper on the spot.

But such measures have done little to solve the underlying supply problem.

Beyond the immediate challenge of supplying food, water, medical supplies and tents to Gazans — many thousands of them still displaced — aid officials said their inability to bring in supplies had set back longer-term recovery efforts.

Some had been distributing vegetable seeds and animal feed to farmers so Gaza could start raising more of its own food, while others had been working on rebuilding the water infrastructure and clearing debris and unexploded ordnance.

None of it was easy, aid officials said, because Israel had restricted or barred items including the heavy machinery required to repair infrastructure, generators and more. Israel maintains that Palestinian militants could use these items for military purposes.

For many Gazans now, the focus is back on survival.

“There’s no bombing at the moment, but I still feel like I’m living in a war with everything I’m going through,” said Nevine Siam, 38, who is sheltering at her brother’s house with 30 other people.

She said her sister’s entire family had been killed during the fighting. Her children ask her to make Ramadan meals like the ones they remember from before the war. But without an income, she can get nothing but canned food in aid packages.

Where she is, she said, there are no celebrations and no festive decorations for the holy month.

“It feels as if the joy has been extinguished,” she said.

Erika Solomon, Ameera Harouda and Rania Khaled contributed reporting.

A 77-year-old former high school teacher, turned out in a neat dress and hat, has been creating a quiet revolution in the villages of Kherson region in southern Ukraine.

Standing before a group of 10 women in a tent in the center of a village in Ukraine’s south last summer, she recounted her ordeal three years ago under Russian occupation.

“What I went through,” said the woman, named Liudmyla, her voice wavering. “I was beaten, I was raped, but I am still living thanks to these people.”

Beginning last year, Liudmyla and two other survivors, Tetyana, 61, and Alisa Kovalenko, 37, have spoken at a series of village meetings to raise awareness about conflict-related sexual violence. The meetings have been among the first efforts by survivors of sexual assault to bring into the open one of the most painful aspects of the Russian invasion of Ukraine: what prosecutors and humanitarian workers say is widespread sexual assault of Ukrainian women under Russian occupation.

Liudmyla and Tetyana asked that their surnames and village names not be published to protect their privacy. Ms. Kovalenko has long spoken openly about the assault on her, which occurred in 2014 during the war with Russian-backed separatists in eastern Ukraine.

Relatively few women in Ukraine have come forward to report cases of rape during the conflict because of the stigma attached to sexual assault in Ukrainian society, which is deeply religious and conservative, especially in rural areas. Prosecutors have registered more than 344 cases of conflict-related sexual violence in Ukraine since the Russian invasion in February 2022, 220 of them women, including 16 underage women.

But women’s groups estimate the real number runs into the thousands, with at least one case in almost every village that has been occupied by Russian troops. United Nations human rights reports have documented dozens of crimes of sexual violence committed by Russian soldiers but have not detailed evidence of any abuses by Ukrainian soldiers. A recent report noted only “two cases of human rights violations against alleged collaborators committed by the Ukrainian authorities.”

Support groups and rights organizations have assisted many women with health services and psychological rehabilitation in the 1,800 settlements recaptured from Russian occupation, but said that not all of them were prepared to give testimony to the police. Many victims remain silent and isolated, and in some cases suicidal, according to members of SEMA Ukraine, part of a global community spanning 26 countries that helps survivors of conflict-related sexual violence with psychological, medical, legal and financial support.

Set up in 2019 by Iryna Dovhan, herself a survivor of a vicious assault by armed separatists in eastern Ukraine in 2014, SEMA Ukraine has encouraged 15 survivors to come forward and join its community over the last six months, bringing the total membership to more than 60 — all survivors of sexual violence in war, she said in an electronic message.

This month Ms. Dovhan is leading a group from SEMA Ukraine to the United Nations Commission on the Status of Women, where they will show a film featuring some of Ukraine’s survivors of sexual violence during the war. They are also presenting an appeal, along with a group of Ukrainian male survivors, for Russia to be named by the United Nations secretary general as a party responsible for crimes of sexual violence committed in Ukraine.

Liudmyla was one of the few who reported her assault to the Ukrainian police. Her daughter, Olha, insisted she report the crime once she escaped from Russian-controlled territory. “I was against it,” Liudmyla recalled in an interview, “but Olha said the Russians have to pay. Of course she was right to expose this crime.”

The attack against her as she described it was particularly brutal. A soldier banged on her kitchen door at 10:30 p.m. one night in July 2022. Scared that he would break the door down, she opened it, and the soldier smashed her in the face with his rifle butt, knocking out her front teeth. He dragged her by the hair, hit her repeatedly with his rifle butt in the ribs and kidneys, and threw her on a couch, throttling her. He made cuts on her abdomen with a knife, and then raped her.

“I was helpless against him,” she said. He left six hours later, saying he would come back in two days and kill her with a bullet.

Badly battered, with four broken ribs, Liudmyla hid at a neighbor’s house and later traveled with a family to Ukrainian-held territory to join her daughter.

She subsequently received a diagnosis of tuberculosis and was hospitalized for six months. “I was depressed, I could not eat,” she said.

But two years after the event, she found purpose in speaking to women’s groups. She said it was the community of survivors at SEMA Ukraine that helped her recover.

The SEMA Network was founded in 2017 by Dr. Denis Mukwege of the Democratic Republic of Congo, who has spent decades working with victims of sexual violence during wartime. The network promotes solidarity within communities, bringing women together to speak out and tell their truths, and helping them stand up for their rights. The word SEMA means “speak out” in Swahili.

“Thanks to this community I started to eat,” Liudmyla said.

“I am holding myself together so that the world knows that they are aggressors, and despots, even to civilians,” she said of the Russian forces.

Ms. Kovalenko, a filmmaker who in 2019 became one of the first women to join SEMA Ukraine, has recorded many women’s testimonies for a documentary. “It’s important to talk in these village communities,” she said. “It can help to reduce the level of stigma, so that people understand that they are not being judged.”

Ms. Kovalenko was detained in an apartment and sexually assaulted by a Russian intelligence officer when covering the early conflict in eastern Ukraine in 2014 as a filmmaker. She was one of the first women in Ukraine to speak publicly and to rights organizations about her ordeal.

“Compared to 2019, it is a revolution that women are speaking out now,” she said. “It’s a real revolution when a woman like Mefodiivna speaks out, and Tetyana.” She referred to Liudmyla by her patronymic, Mefodiivna, in a term of respect.

Tetyana, who owns a store with her husband, Volodymyr, in a village in the Kherson region, gave her first interview to a journalist from The New York Times, and spoke for the first time at a village meeting last summer.

Russian soldiers occupying their village frequently visited their store, and when it was closed they would break in. Then one night in April 2022, two soldiers broke into their house. They shot at Volodymyr — he managed to dodge the bullet and hide, she said — but they caught Tetyana as she tried to run away. They pinned her down in the yard, pulling her hair and beating her, and then one of the men raped her. They left only when an artillery attack began on the village.

After months of counseling, and stays in the hospital and refuges, Tetyana said she had discarded feelings of rage and hate but still could not bear the physical touch of a man, including that of her husband. She was unsure whether she would manage to speak at the meeting organized by SEMA Ukraine.

She finally did speak, but kept to a prepared script, explaining the stages of trauma a victim of sexual assault will display, and how to help them.

The most important consideration, she said, was to reassure victims that they are safe.

Over the longer term, she compared the trauma of sexual violence to sand clogged in an hourglass. “If it is blocked, then nothing will pass through,” she said.

It was clear she spoke from experience, but she was talking to women in the audience who had also lived through the terror of occupation. One woman said she had been buried under rubble when her house was hit in a shell strike, while another said she had been forced to host Russian soldiers in her home.

“All of us have some level of vicarious trauma after living in occupied communities,” Tetyana said. “You need to work out your pain so it does not stay inside of you for too long.”

Germany’s next chancellor, Friedrich Merz, set European pigeons flying in circles when he suggested last month that given rising mistrust in President Trump’s commitment to NATO, he wanted to talk to France and Britain about extending nuclear deterrence over Germany.

Warning that a “profound change of American geopolitics” had put Poland, as well as Ukraine, in an “objectively more difficult situation,” Prime Minister Donald Tusk of Poland suggested the same, while hinting that Poland, with its long history of Russian occupation, might eventually develop its own bomb.

Then Poland’s president, Andrzej Duda, said this week that it was time for the United States to consider redeploying some of its nuclear weapons from Western Europe to Poland. “I think it’s not only that the time has come, but that it would be safer if those weapons were already here,” Mr. Duda told the Financial Times.

The uproar was immediate, given the sensitivity and complications of the nuclear issue and the whole concept of extended deterrence — the willingness of a nuclear-armed country to use its nuclear weapons in defense of a nonnuclear ally. That commitment is at the heart of NATO’s Article Five, promising collective defense, and hinges on the massive American nuclear arsenal.

Mr. Trump and his officials say they remain committed to extending the American nuclear umbrella over Europe, the vital deterrent to any serious Russian aggression, and to the alliance itself. But his evident hostility toward Europe has so unnerved America’s traditional European allies that it has provoked strong doubts that they can depend on the United States.

There are fears that talking too much about a European replacement, let alone trying to construct one, would only encourage Mr. Trump to withdraw his pledge. Even so, European allies are now engaged in the most serious debate in generations about what Europe’s nuclear defense should be.

Like many things when it comes to European defense, replacing the American commitment would not be easy.

Today France and Britain are the only two Western powers in Europe who possess nuclear weapons. For others, like Germany, to join the nuclear club would be expensive, require leaving the Nuclear Nonproliferation Treaty and could seem more threatening to Moscow, raising risks rather than lowering them.

But together, the French and British have only about 500 warheads compared with some 3,700 in the American arsenal, with another 1,300 or so waiting to be deactivated. The Americans also have what is known as the “triad” — nuclear weapons on land-based missiles, bombers and submarines.

The French have no land-based missiles but do have nuclear-equipped bombers and submarines, while the British have only submarines.

And only the French nuclear arsenal is truly independent of the United States, technically and politically. France has always refused to join NATO’s nuclear planning group, keeping sole authority on the use of its weapons in the hands of the French president, currently Emmanuel Macron.

The British deterrent depends on American Trident II missiles, launching mechanisms and maintenance, raising at least the question of whether the British government has full authority to launch these weapons.

French doctrine has always been kept a bit vague, part of the uncertainty that is the heart of deterrence. “We have a pretty good idea what the French will not do, but not such a clear understanding of what they are willing to do,” said Claudia Major, head of trans-Atlantic security studies for the German Marshall Fund.

Since 2020, Mr. Macron has sometimes spoken of France’s vital national interests as having “a European dimension,” without specifying what that is. Earlier this month, he announced a “strategic debate on using our deterrence to protect our allies on the European continent.”

“But how far does that ‘European dimension’ go?” Ms. Major asked. “The French won’t define it and of course don’t want Russia to know.”

The security of neighboring Germany and perhaps Poland would likely qualify as vital French national interests, said Erik Jones, director of the Robert Schuman Center at the European University Institute.

But it is far from clear that a quick conventional Russian attack on Estonia or Lithuania would prompt a French nuclear threat or response. “The vital interests of France do not reach that far,” he said.

The French nuclear deterrent is not meant to provide an American-style extended deterrence on the cheap, said Camille Grand, a former French and NATO defense official. But it does provide another degree of uncertainty for Moscow that complements and even strengthens NATO nuclear policy, he said.

Since both France and Britain are European, their national interests are more likely to stretch to the European neighborhood than is the case for the distant United States, Mr. Grand argued.

Then there is the question of the next French president. Should it be Marine Le Pen, the head of the far-right National Rally, she might have a narrower view of French interests. That could undermine the credibility of an extended French nuclear deterrent in the same way that Europeans have become anxious over Mr. Trump’s commitment.

Still, with both bombers and submarines, France maintains an “escalation ladder,” with the ability to threaten use without doing so. For example, in February 2022, after the Russian invasion of Ukraine, France put a third nuclear submarine out to sea, “a quiet but explicit message that the Russians saw,” Mr. Grand said.

As Mr. Merz and the Polish leaders suggested, France might also consider “nuclear sharing,” as the Americans now do. There are five European countries — Germany, Italy, Belgium, the Netherlands and Turkey — that currently host American B61 nuclear bombs and have their own airplanes to deliver them.

Poland would like to be a sixth. While French nuclear-capable bombers have been refueled by Italy, for instance, for France to decide to place some of its nuclear weapons and bombers in other countries would be a break with its current doctrine. In any case, France and its president would retain total control over their use.

Submarines by themselves do not provide an escalation ladder, because they are supposed to remain hidden, and either fire missiles or don’t. That is one reason British officials are considering restoring the air leg of their deterrent. Ideally, the British would also benefit from another nuclear-capable submarine, so more than one can be at sea. But the expense is enormous.

And there is no way to share a submarine with another country, the way an air-launched bomb or missile can be shared.

In the end, the core of NATO’s nuclear deterrent remains the United States, said Ivo Daalder, a former U.S. ambassador to NATO.

The question for him is less the number of warheads than the credibility of the deterrence. “How to make a deterrent versus Russia credible when you’re an ocean away and convince allies you’re willing to make the ultimate sacrifice for them?” he asked. “Unfortunately, Trump answers those questions without even raising them.”

Given all the uncertainty, Germany might have to go nuclear itself, said Thorsten Benner, director of the Global Public Policy Institute. “So far talk of a German bomb has been limited to fringe types, but now it becomes more mainstream,” he said. But he prefers discussing nuclear sharing with France, with French bombers on German bases.

Matthew Kroenig, a former defense department official who directs the Scowcroft Center for Strategy and Security at the Atlantic Council, thinks the debate has been beneficial to get Europeans to take defense more seriously.

“NATO allies should do a lot more of the nuts and bolts of conventional defense, but some high-end stuff like nuclear deterrence — only the United States can provide,” he said.

Ms. Major has another concern, widely shared. “The more we do for defense the better for us,” she said. “But does it send the wrong signal and have the unintended consequence of America leaving? It’s the decoupling argument that we fear so much.”

To hear President Trump and some of his closest supporters tell it, South Africa is a terrible place for white people. They face discrimination, are sidelined from jobs and live under the constant threat of violence or having their land stolen by a corrupt, Black-led government that has left the country in disarray.

The data tell a different story. Although white people make up 7 percent of the country’s population, they own at least half of South Africa’s land. Police statistics do not show that they are any more vulnerable to violent crime than other people. And white South Africans are far better off than Black people on virtually every marker of the economic scale.

Yet Mr. Trump and his allies have pushed their own narrative of South Africa to press an argument at home: If the United States doesn’t clamp down on attempts to promote diversity, America will become a hotbed of dysfunction and anti-white discrimination.

“It plays into the fears of white people in America and elsewhere: ‘We whites are threatened,’” Max du Preez, a white South African writer and historian, said of Mr. Trump’s description of his country.

But, Mr. du Preez added, white people have flourished since the end of apartheid in 1994.

The parallels between South Africa’s attempts to undo the injustices of apartheid and the long struggle in the United States to address slavery, Jim Crow laws and other forms of racial discrimination have become a common refrain among some Trump supporters.

Ernst Roets, a white activist and author in South Africa, said that when he spoke to like-minded conservatives in the United States, they often told him, “Oh, yes, we need to look at South Africa, because that’s what’s in store for us if we’re not cautious.”

After apartheid fell three decades ago, South Africa’s democratic government rose to power on a promise to undo the inequities of a system that had left much of the country’s Black majority in squalor. Yet President Nelson Mandela largely allowed white South Africans to keep their wealth, in an effort to maintain a peaceful transition to democracy.

His party, the African National Congress, has passed laws to try to close the gap for Black people. Most recently, South Africa enacted one that allows the government to take private land in the public interest, sometimes without providing compensation.

The law has not yet been used, but some white South Africans — and Mr. Trump — say it unfairly targets the country’s landowners and commercial farmers, who remain mostly white despite decades of anti-apartheid policies.

Mr. Trump has built his political identity in part as a protector of white America. He has fought to save symbols of the Confederacy in the South, blasted racial sensitivity training as “un-American propaganda” and publicly defended white supremacists.

Cutting off aid to most of Africa while championing Afrikaners — the white ethnic minority in South Africa that led the apartheid government — appears to be the latest illustration of Mr. Trump’s commitment to white interests.

Last month, the president signed an executive order granting refugee status to Afrikaners and suspending all aid to South Africa, partly in response to its land-reform law. He said on social media last week that the United States would offer a rapid pathway to citizenship to South African farmers, many of whom are Afrikaner. Then on Friday, Secretary of State Marco Rubio called South Africa’s ambassador to the United States, Ebrahim Rasool, “a race-baiting politician who hates America” and expelled him.

“Trump is signaling to white people everywhere that he will use his power to protect and advance their interests, no matter the facts,” said Khalil Gibran Muhammad, a professor of African American studies at Princeton University.

Some Afrikaners have welcomed Mr. Trump’s embrace. Activists traveled to Washington last month to lobby his administration for more support. A White House official described the Afrikaner delegation as “civil rights leaders.”

Many of Mr. Trump’s allies have long spotlighted the grievances of Afrikaners. Elon Musk, who was born in South Africa but is not of Afrikaner descent, has accused the country’s government of promoting racist laws, and falsely claimed that white farmers in South Africa were being killed every day.

After Mr. Roets appeared on Tucker Carlson’s Fox News show in 2018, Mr. Carlson posted on social media that “White farmers are being brutally murdered in South Africa for their land.”

Mr. Carlson later ran a segment describing land seizures and homicides. Mr. Trump, who was in his first term at the time, then tagged Mr. Carlson in a social media post in which he said he was ordering an investigation into farm seizures “and the large scale killing of farmers” in South Africa, though to this day no farms have been seized by the government.

In Mr. Trump’s orbit, these themes are now being recirculated as warning signs for the United States.

Mr. Roets said in an interview that he had become close to Jack Posobiec, the American far-right influencer who recently accompanied Defense Secretary Pete Hegseth on a trip to Europe.

During an earlier conversation with Charlie Kirk, an influential Trump ally, Mr. Posobiec said that South Africa was in shambles because of its laws meant to produce racial equity. He added that the United States was headed down the same path by hiring “on the basis of race, gender and sexual orientation.”

Many South African voters, regardless of their race, agree that the African National Congress has created a country plagued by corruption, poor infrastructure, high crime and inequality, with persistent poverty among Black people. In the last election, the party lost its outright majority in Parliament for the first time since the end of apartheid.

Analysts note that the party went to great lengths to embrace market-oriented policies that allowed white South Africans to maintain their economic power. In fact, many South Africans criticize Mr. Mandela for not requiring a more aggressive redistribution of white-owned land to Black South Africans, whose families had been forced off of it during apartheid and colonial times.

Supporters of the new land law hope that it will speed up the long-held goal of giving back more land to Black South Africans.

But to Mr. Trump, it is Afrikaners who are the “victims of unjust racial discrimination,” as he said in his executive order signed last month.

Descended primarily from Dutch colonizers who arrived in southern Africa in 1652, Afrikaner people became international darlings in the early 1900s as a small tribe that stood up to the mighty British Empire in battles over territory (though they ultimately lost the war). The ruling British then looked down on Afrikaners as uncouth, and those fights sowed bitter divisions between South Africa’s two largest white populations that exist to this day.

While the president has generally tried to prohibit refugees or asylum seekers from entering the United States, he has carved out a special avenue for some white Africans to come into the country.

That has not necessarily lined up with the wishes of his target audience. Many Afrikaners have said that while they appreciate Mr. Trump supporting their claims of persecution, they would rather stay in South Africa, which they consider their rightful home.

Willem Petzer, an Afrikaner online influencer whose social media posts have been shared by Trump supporters, said he was considering Mr. Trump’s offer. But he said he hoped more than anything that South Africa’s government would end what he called its racism toward people who look like him.

“By the time I was a conscious human being, apartheid had been long gone,” Mr. Petzer, 28, said. “All I have ever known is discrimination against white people.”

That sort of rebranding of Afrikaners as victims has great resonance among the American far-right, said Mr. du Preez, the Afrikaner writer and historian, who founded the first anti-apartheid newspaper in Afrikaans.

“They’re playing on the thing of the white Christian civilization being threatened,” he said. “And that has a lot of appeal among the evangelicals and others in the United States.”

Zolan Kanno-Youngs contributed reporting from Washington.

Five years after it left the European Union, Britain may have finally found a new role on the global stage — a gig that looks curiously like its old one.

In the frantic few weeks since President Trump upended the trans-Atlantic alliance with his overtures to Russia and rift with Ukraine, Britain’s prime minister, Keir Starmer, has tried to act as a bridge between Europe and the United States.

Mr. Starmer and his top aides counseled President Volodymyr Zelensky of Ukraine in phone calls and face-to-face meetings about how to mend fences with Mr. Trump after their rancorous White House meeting. The prime minister has energetically lobbied the American president for security guarantees to deter President Vladimir V. Putin of Russia from future aggression.

In his high-wire diplomacy, Mr. Starmer is reviving a role Britain routinely played before Brexit. He bears comparison to Tony Blair, a previous Labour prime minister, who tried to mediate between President George W. Bush and European leaders in the fraught lead-up to the Iraq War in 2003.

Mr. Blair’s bridge building didn’t end well, of course: France and Germany refused to join Mr. Bush’s “coalition of the willing” against Iraq, and Britain’s lock-step alignment with the United States frayed its relations with its European neighbors.

Now, as Mr. Starmer puts together a new “coalition of the willing” to protect Ukraine, he faces a similarly tricky balancing act. He is sticking close to the United States while trying to marshal a European military deterrent formidable enough to persuade Mr. Trump to provide American air cover and intelligence support to peacekeeping troops.

On Saturday, Mr. Starmer convened a video conference with 30 leaders, from Europe, NATO, Canada, Ukraine, Australia and New Zealand, to muster support for his coalition, which Britain is spearheading with France. He said military officials would meet again on Thursday to begin an “operational phase,” though he did not give details about the mission of the force, nor did he announce that any other countries had committed troops to it.

“I’ve indicated a willingness for the United Kingdom to play a leading role in this,” Mr. Starmer said at a news conference after the meeting. “If necessary, that would be troops on the ground and planes in the sky.”

Mr. Starmer said he would continue pressing Mr. Trump for American security guarantees — a lobbying effort that he shares with President Emmanuel Macron of France. “I’ve been clear that it needs to be done in conjunction with the United States,” he said. “We are talking to the U.S. on a daily basis.”

Whether Mr. Starmer will succeed in turning around Mr. Trump is anybody’s guess, given that the president has veered between bitter denouncements of Ukraine and threats to impose sanctions on a recalcitrant Russia. Mr. Putin reacted warily to an offer of a 30-day truce made by Ukraine and the United States this week, while rejecting all talk of a European peacekeeping force.

“Of course there’s a risk,” said Peter Ricketts, a British diplomat who served as national security adviser to Prime Minister David Cameron. “But I think Starmer sees a greater risk of an avoidable catastrophe.”

Mr. Blair, he said, failed as a bridge because the divisions between European nations over Iraq were insurmountable. Mr. Starmer’s challenge is an erratic American president, who seems determined to reset relations with Russia and is openly hostile toward the European Union.

“Starmer’s going to do his very best not to have to choose between Europe and the U.S.,” Mr. Ricketts said. Dealing with Mr. Trump, he added, “makes him vulnerable to sudden lurches, but so far, he’s managed to stay on the tightrope.”

Mr. Starmer, he said, has been helped by his seasoned and widely respected national security adviser, Jonathan Powell, who traveled to Kyiv, the Ukrainian capital, to help lay the groundwork for Mr. Zelensky’s rapprochement with the White House, and to Washington this week to consult with Mr. Trump’s national security adviser, Michael Waltz.

A onetime chief of staff to Mr. Blair, Mr. Powell served as Britain’s chief negotiator for the Good Friday Agreement, which ended decades of sectarian violence in Northern Ireland. He was also on hand for Mr. Blair’s fruitless effort to bring France and Germany along in the military campaign against Iraq.

Even before the crisis over Ukraine erupted, Mr. Starmer’s government was seeking closer ties with the continent, not just on defense and security but also on trade and economic policy.

But thanks to Brexit, Mr. Trump appears to place Britain in a different category from the European Union, which may help make Mr. Starmer a more effective broker. The president has suggested, for example, that he may not target Britain with sweeping tariffs, though he did not exempt it from a global tariff on steel and aluminum.

“Having one foot in, one foot out is a good thing for the U.K. in the present context,” said Mujtaba Rahman, an analyst at the political risk consultancy Eurasia Group, “but only if we remain in the current state of phony war.”

“If it becomes a real trans-Atlantic rift,” Mr. Rahman continued, “then it is better to have the protecting power that the E.U. offers, at least in some areas. And in such a context, the U.K. would steer things better if it had two feet in.”

At first, Mr. Starmer’s re-engagement with the bloc was distinctly a half step. After coming to power last July, he set about patching up post-Brexit relations in various European capitals but ruled out two conspicuous measures that could significantly boost trade: rejoining the bloc’s giant single market and its customs union.

His cautious approach, analysts say, is rooted in a fear of angering Brexit-supporting voters and of giving ammunition to Nigel Farage, the Brexit champion and leader of the anti-immigration party, Reform U.K., which has surged in opinion polls.

But the shock waves caused by Mr. Trump’s recent pronouncements on Ukraine and Russia have swept away some of the roadblocks to a broader reset. They have given Mr. Starmer political cover, with even those on the right in Britain acknowledging the need for greater coordination on Europe’s defense.

“It changes the whole context and puts everything else in perspective,” said Mr. Ricketts, who served as ambassador to France.

Ivan Rogers, a former British ambassador to the European Union, said Mr. Starmer’s diplomatic heavy lifting had impressed other European leaders, who had become used to a Britain that was either absent or vaguely antagonistic.

“All of that has reminded people that the Brits have re-engaged, and they might be more serious,” Mr. Rogers said. “You are now facing such an existential crisis in the E.U. that the mood has changed a bit.”

That could open a path to more profound British re-engagement, especially if the Europeans decide to increase cooperation on military spending by creating a new initiative outside the existing structures of the European Union. Such an initiative could involve countries, including Britain, agreeing to common standards on issues like military subsidies and weapons procurement.

That would essentially “create a defense single market, which has never been there before,” Mr. Rogers said.

For all the potential upside, Mr. Rogers, who worked in Downing Street during the Iraq War, said he worried that Britain’s role as a trans-Atlantic bridge would be hampered by its efforts to use its post-Brexit status to avoid the tariffs imposed by Mr. Trump.

“My worry is that it could appear to others that the U.K. wants to have it both ways,” Mr. Rogers said. “We want to be a bridge, have the trans-Atlantic alliance, be central to it, while simultaneously making the argument that we are very different from the E.U., and the U.S. can exempt us from its tariff action.”

“It’s a little difficult,” he said, “to run both those arguments at once.”

Mark Carney, who has never held elected office but has a long résumé in economic policymaking and investing, was sworn in Friday morning as Canada’s 24th prime minister. He will have no time to ease into his role.

Canada is experiencing a period of severe instability as its relationship with its closest ally, the United States, has been plunged into an extraordinary crisis since President Trump was elected and began unleashing attacks on its economy and sovereignty.

Mr. Carney will attempt to negotiate with Mr. Trump, who has unfurled a slew of tariffs and threats on Canada including a desire to take over the country entirely, while simultaneously heading straight into a campaign for a federal election.

He does not hold a seat in Parliament, and his party controls only a minority of the seats in the House of Commons, which means he has little choice but to immediately call for a federal election, likely to take place by May.

Mr. Carney, who turns 60 on Sunday, replaces Justin Trudeau who led Canada for nearly a decade. He was elected as Liberal Party leader on Sunday by some 152,000 members of the party, securing 86 percent of the vote.

In a traditional ceremony that involved pledging allegiance to King Charles III, Mr. Carney was sworn in by Mary Simon, Canada’s governor-general, who represents the king as the official head of state. Ms. Simon is the first Indigenous person to serve in that role.

Mr. Carney, speaking to reporters after he was sworn in, called Mr. Trump’s threats to make Canada the 51st state “crazy.”

He has no plans for now, he said, to meet with Mr. Trump. Instead, his focus will be on strengthening Canada’s economy against trade threats.

“We know that by building together, we can give ourselves far more than anyone else can take away,” he said.

His first act on Friday afternoon was to sign an order immediately eliminating a widely unpopular consumer carbon tax introduced in 2019 under Mr. Trudeau.

Mr. Carney had served as governor of the Bank of Canada during the global financial crisis of 2008 and later as governor of the Bank of England — the first and, so far, only foreigner to be hired to the job — from 2013 and through the Brexit transition.

Before becoming a central banker, he worked at Goldman Sachs for more than 10 years. Since leaving the Bank of England he has served in top positions on corporate boards and has emerged as a key global advocate for green investment.

Mr. Carney has made it clear that he plans to continue taking a hard line against Mr. Trump, while also trying to reach a trade deal with the president. Canada has applied two rounds of retaliatory tariffs against U.S. exports and said it was prepared to do more.

“My government will keep our tariffs on until the Americans show us respect — and make credible, reliable commitments to free and fair trade,” he told the party faithful in Ottawa on Sunday as he accepted the role of party leadership.

And in a sign that he is looking for new best friends for Canada now that its relationship with the United States is badly frayed, his first overseas visits will be to London and Paris.

Dealing with the complex problems that Mr. Trump’s statehood threats and tariffs create for Canada will leave little time for anything else, but Mr. Carney has made policy promises that suggest he is a centrist.

He has vowed to introduce an era of fiscal prudence and to cut taxes, while leveraging his business experience to help Canada attract investments that can help boost the country’s economy.

Mr. Carney will also need to turn his attention to pressing domestic issues, like a persistent high cost of living and the effects of record immigration that spurred Mr. Trudeau’s resignation.

But the economic fallout from the suite of tariff measures imposed by Mr. Trump, will dominate Mr. Carney’s first days in office.

He will need to try to stop Mr. Trump from bringing in fresh surcharges on more Canadian goods as he has threatened. Economists say they expect that the current measures taken against Canada by the U.S. administration, as well as the slowdown in investment that comes from the uncertainty around what will happen next, will hurt the Canadian economy and could push it into a recession.

Then there is the looming election. Mr. Carney will need to prove that despite never having run for political office, he is still the best person for the job, not just to a group of party members who broadly agree with him but to the entire electorate.

In the federal election he will face off against Pierre Poilievre, the Conservative leader who has helped his party gain a robust lead in public opinion polls and collect almost double the amount of fund-raising dollars as the Liberals in 2024.

Mr. Trump’s arrival in the White House, however, has upended the political landscape.

A lifelong politician who knows how to deliver a punchy slogan, Mr. Poilievre, 45, is trying to pivot his messaging, political analysts say, to position himself as the strongest candidate to take on Washington, while not alienating pro-Trump conservatives in Canada.

Mr. Poilievre’s main angle of attack had long been to present Canadians with all the ways that the Liberal Party had “broken” Canada, with a focus on crime, housing prices and a surge in immigration.

“That is the choice: more of the same,” Mr. Poilievre told reporters on Friday after Mr. Carney was sworn in. “Or Canada-first change for the Canadian people.”

But Mr. Trump’s ascent and his attitude toward Canada, coupled with the resignation of Mr. Trudeau, who had become deeply unpopular, have nearly evaporated the Conservatives’ lead in a remarkable reversal.

Several recent opinion polls have shown that, under Mr. Carney’s leadership, the Liberals would have a chance of eking out a victory.

From his expansive qualifications in the finance world, there’s little doubt of Mr. Carney’s ability to get his message across in a boardroom or a monetary policy meeting. In his central banking roles he was often seen as being sermonic, and at times dismissive of the news media.

But he’ll need to find a common touch and a different level of engagement to be able to campaign effectively.

Mr. Carney’s challenge will be to quickly master “retail politics” — the art of energizing a room with a speech, making individual supporters feel important and heard and finding a way to engage with the news media that gets his point across clearly, said Fen Hampson, a professor of international affairs at Carleton University in Ottawa.

“Those glad-handing skills do not come automatically to someone who’s spent his life being a banker,” Mr. Hampson said. “His Achilles’ heel is that his communication skills and his retail politics skills are not finely honed yet.”

In forming a cabinet, Mr. Carney has maintained the roughly 50-50 split of men and women, a standard Mr. Trudeau set when announcing Canada’s first gender-balanced cabinet after he was elected in 2015.

The foreign minister, Melanie Joly, will remain in her position and Dominic LeBlanc, a close friend of Mr. Trudeau, will be the new minister of international trade, taking a central role in tariff discussions along with the new finance minister, François-Philippe Champagne.

The former finance minister, Chrystia Freeland, who was the runner-up in the Liberal leadership race, will remain in the cabinet as minister of transport and internal trade.