Keir Starmer Talks Trump, Russia-Ukraine War and the Fragile Europe-US Alliance

With a staccato burst, a horn sounded in the control room of the H.M.S. Vanguard, sending the crew of the nuclear-armed Royal Navy submarine to battle stations. The voice of the commanding officer crackled over the intercom. “Set condition 1SQ,” he said, ordering its battery of ballistic missiles to be readied for launch.

It was just a drill, conducted last Monday for a visiting V.I.P., Prime Minister Keir Starmer. But Mr. Starmer had reason to pay close attention when he was shown where the submarine’s launch key is stored: The prime minister is the only person in the United Kingdom authorized to order a nuclear strike.

“You’re looking for the ideal conditions?” Mr. Starmer asked softly, as the captain explained how the Vanguard must be maneuvered to the right depth to launch its Trident missiles. Mr. Starmer leaned forward in the captain’s chair, the blue glow from a bank of screens reflected in his eyeglasses.

Later, after he had climbed a 32-foot ladder to the submarine’s deck, Mr. Starmer reflected on its nearly seven-month-long mission. Prowling silently in the depths of the Atlantic Ocean, it is designed to deter a nuclear conflict with Russia (at least one of the four Vanguard-class submarines is always on patrol). At a time when Europe’s capacity to defend itself has come under criticism, not least from President Trump, Mr. Starmer said these mighty boats were an ironclad symbol of Britain’s commitment to NATO.

“Twenty-four hours, 365 days, year after year after year, for 55 years,” Mr. Starmer told me after we had cast off and the Vanguard steamed toward its home port in Scotland. “It has kept the peace for a very long time.”

Back on a tugboat, taking us to shore in the Firth of Clyde, Mr. Starmer sat alone, staring out a window at the gathering clouds. It has been a defining, if sobering, few weeks for the 62-year-old British leader: Swept into power eight months ago on a tide of discontent about the cost of living, he now finds himself fighting to avert a rupture of the post-World War II alliance between Europe and the United States.

“In our heart of hearts, we’ve known this moment was coming from just over three years ago, when Russian tanks rolled across the border” of Ukraine, Mr. Starmer said of Europe’s heightened vulnerability and the strains in the NATO alliance. “We have to treat this as a galvanizing moment and seize the initiative.”

The crisis has transformed Mr. Starmer, turning a methodical, unflashy human rights lawyer and Labour Party politician into something akin to a wartime leader. With debates over welfare reform and the economy largely eclipsed for now by fears about Britain’s national security, Mr. Starmer invoked Winston Churchill and, in a nod to his party, Clement Attlee, the first postwar Labour prime minister, as he described Britain’s singular role in a more fractured West.

“Many people are urging us to choose between the U.S. and Europe,” he said in one of three conversations last week. “Churchill didn’t do it. Attlee didn’t do it. It’d be a big mistake, in my view, to choose now.”

Pausing for a moment, Mr. Starmer added, “I do think that President Trump has a point when he says there needs to be a greater burden borne by European countries for the collective self-defense of Europe.”

The immediate question is whether Britain and Europe will play a meaningful role in Mr. Trump’s negotiations with President Vladimir V. Putin of Russia. To ensure that they do, Mr. Starmer is trying to assemble a multinational military force that he calls a coalition of the willing. The goal, he says, is keep Ukraine’s skies, ports and borders secure after any peace settlement.

“I don’t trust Putin,” Mr. Starmer said. “I’m sure Putin would try to insist that Ukraine should be defenseless after a deal because that gives him what he wants, which is the opportunity to go in again.”

Britain faces hurdles on every front: Russia has rejected the idea of a NATO peacekeeping force. Mr. Trump has yet to offer security guarantees, which Mr. Starmer says are crucial before countries will commit troops. Aside from Britain and France, no other European country has done so, even as Mr. Starmer led the first military planning meeting for the coalition on Thursday.

Senior British military and defense officials said they expected that ultimately, multiple countries would contribute planes, ships or troops to the effort. But regardless of the political and diplomatic uncertainties, Mr. Starmer said he felt he had little choice but to get ahead of the pack.

“If we only move at the pace of the most cautious,” he said, “then we’re going to move very slowly and we’re not going to be in the position we need to be in.”

Behind Mr. Starmer’s whirlwind of diplomacy is an even more elusive goal: persuading Mr. Trump of the value of NATO, the 75-year-old alliance the president disparages as a club of free riders, sheltering under an American security umbrella but failing to pay their fair share.

Unlike President Emmanuel Macron of France or Germany’s incoming chancellor, Friedrich Merz, Mr. Starmer has not called for Europe to chart an independent course from the United States on security. He insists that the “special relationship” is unshakable and that, in any case, British and American forces are deeply intertwined (the United States supplies the Trident missiles on British submarines).

Mr. Starmer has painstakingly cultivated Mr. Trump, phoning him every few days and turning up at the White House last month with a signed invitation from King Charles III for a state visit to Britain. The prime minister said Mr. Trump told him how much he treasured his meetings with Queen Elizabeth II.

The two men could hardly be less alike: Mr. Starmer, disciplined and reserved, with left-wing political roots; Mr. Trump, impulsive and expansive, with habits and instincts that shade into the regal. Yet they seem to have established a rapport. Mr. Trump occasionally calls him on his cellphone, one of Mr. Starmer’s aides said, to discuss favorite topics like his golf resorts in Scotland.

“On a person-to-person basis, I think we have a good relationship,” Mr. Starmer said of Mr. Trump, whom he first met over dinner in Trump Tower last fall. “I like and respect him. I understand what he’s trying to achieve.”

As for Mr. Trump’s actions — from imposing a 25 percent tariff on British steel to berating President Volodymyr Zelensky of Ukraine — Mr. Starmer said he recognized that the president had generated “quite a degree of disorientation.” The right response, he said, was not to get provoked by it.

“On the day in which the Oval Office meeting between President Trump and President Zelensky didn’t go particularly well, we were under pressure to come out very critically with, you know, flowery adjectives to describe how others felt,” Mr. Starmer recalled. “I took the view that it was better to pick up the phone and talk to both sides to try and get them back on the same page.”

Mr. Starmer dispatched his national security adviser, Jonathan Powell, to Kyiv, the Ukrainian capital, to coach Mr. Zelensky on how he could mend fences with Mr. Trump. In multiple sessions, two senior British officials said, they crafted language to mitigate Mr. Zelensky’s anxieties about a cease-fire in which the Russians would keep shooting.

Mr. Starmer then phoned Mr. Trump to relay the progress in Kyiv and lay the groundwork for a call between him and Mr. Zelensky. When the presidents spoke again, Mr. Zelensky threw his support behind Mr. Trump’s peacemaking effort.

In offering himself as a bridge, Mr. Starmer is trying to reclaim a role that Britain played for decades before it voted to leave the European Union in 2016. It showed, he said, that after a period in which Britain had been “disinterested” and “absent” from the world stage, “we’re back, if you like.”

But there are limits to Britain’s role in a post-Brexit world: The E.U. said it would exclude British weapons manufacturers from a defense fund worth 150 billion euros ($162 billion), unless Britain signs a security partnership agreement with Brussels. Britain, analysts say, will find it harder to act as a bridge if Mr. Trump spares it from more sweeping tariffs that he has vowed to impose on the European Union.

For now, Mr. Starmer’s statesmanship has buoyed his poll ratings and won him praise across the political spectrum. After a fitful start, in which he was dogged by a torpid economy, Mr. Starmer said the crisis “had injected an urgency” into his government.

How long that will last is anyone’s guess. Britain’s economy continues to sputter and Mr. Starmer has faced a backlash over decisions like cutting payments to help retirees with winter heating costs. The benefits of being a statesman, analysts say, can be evanescent if domestic woes keep piling up.

Even the fire at an electrical substation in London on Friday, which shut down Heathrow Airport and threw travel plans for tens of thousands into chaos, is a reminder of how events can temporarily swamp a government’s agenda.

Painful trade-offs loom, further down the road. Mr. Starmer has pledged to increase military spending to 2.5 percent of Britain’s gross domestic product by 2027, financed with a cut to overseas development aid. It is not clear how Britain will pay for a promised further increase to 3 percent of G.D.P. within a decade.

“We’ve all enjoyed the peace dividend,” Mr. Starmer said, noting that Europe is moving into a darker era. “I don’t want to veer into scaremongering,” he said, but added, “We need to think about defense and security in a more immediate way.”

Three days after the submarine visit, Mr. Starmer took part in a keel-laying ceremony for a new fleet of ballistic missile submarines, being built at a shipyard in Barrow-in-Furness, in northwest England. Four Dreadnought-class vessels, each almost the length of St. Paul’s Cathedral, are scheduled to go into service in the early 2030s, at an estimated cost of 41 billion pounds ($53 billion).

Standing in the cavernous factory, with the aft section of a submarine towering above him, Mr. Starmer expressed pride in this statement of British might. But it was also a reminder of the stretched state of its military.

The Vanguard-class submarines being replaced by the Dreadnoughts are nearly 30 years old — “pretty old kit,” in Mr. Starmer’s words — which necessitates prolonged maintenance periods. That has extended the patrols for the other vessels in the fleet and put acute pressure on their roughly 130-person crews.

The strain was on display during Mr. Starmer’s visit to the Vanguard, which set a Royal Navy record for longest patrol. Sailors said the food, excellent at first, deteriorated as the submarine’s provisions dwindled. Four were returning to spouses who’d had babies while they were away. Others lost family members, only learning the news from the captain on the eve of their return.

“It is with huge respect to the team,” that they survived seven months at sea, Mr. Starmer said after stepping gingerly off the submarine’s weathered deck. “But we shouldn’t be celebrating it.”

“This has doubled my resolve to ensure we go further and faster in our capabilities,” he said, “to make sure they are not put in that position again.”