By EMMA BURROWS

LONDON (AP) — President Donald Trump is pushing Ukraine to cede territory to Russia to end the war, threatening to walk away if a deal becomes too difficult — and causing alarm bells in Europe about how to fill the gap.

Ukraine’s European allies view the war as fundamental to the continent’s security, and pressure is now mounting to find ways to support Kyiv militarily — regardless of whether Trump pulls out.

Trump has repeatedly lashed out at Ukrainian President Volodymyr Zelenskyy, accusing him of prolonging the “killing field” by pushing back on his demand that Ukraine hand over occupied Crimea to Moscow.

Trump’s land-for-peace plan would mark a significant shift in the post-World War II order, ripping up conventions that have long held that borders should not be redrawn by force.

“It took a World War to roll back de jure annexations and 60 million people died,” said François Heisbourg, special adviser at the Foundation for Strategic Research in Paris, referring to the pre-war annexation of Austria by Nazi Germany.

“Europeans will not accept it” and Ukraine will not either, he said.

Can Ukraine fight without U.S. support?

Diplomats and experts described various scenarios if the U.S. decides to walk. They range from the U.S. ceasing direct aid to Ukraine — but allowing European nations to pass on critical American intelligence and weapons to Kyiv — to Trump banning transfers of any American technology, including components or software in European weapons.

Any withdrawal of U.S. military aid to Ukraine could create serious difficulties for Europe, analysts and diplomats told The Associated Press. Kyiv’s ability to keep fighting would depend on European political will to muster money and weapons — and how quickly the gaps left by Washington can be filled.

If it were easy, Europe would “already be doing things without America,” said a European diplomat, who spoke on condition of anonymity to discuss the sensitive matter.

Where would the money come from?

No new U.S. aid package for Ukraine has been approved since Trump came into office, even as European nations have collectively provided Ukraine with more aid than Washington, according to the Keil Institute.

Europe has contributed around $157 billion, some $26 billion more than the U.S., although Washington slightly outpaces Europe when it comes to military aid, the Germany-based institute said.

It will be hard, but there are ways Europe can find cash to fund Ukraine — including seizing frozen Russian assets — but “money isn’t what you shoot bullets with,” Heisbourg said.

Europe’s “big mistake” was undertaking major military downsizing following the Cold War and thinking “this war started in February 2022 and not in February 2014,” when Moscow invaded and then annexed Crimea, said Thomas Gomart, director of IFRI, a French international affairs think tank.

Europeans are scrambling to acquire weapons for themselves and for Ukraine, while confronting constraints on production capacity, a fragmented defense industry and a decades-long reliance on the U.S.

Some extra production capacity could come from Ukraine, which has ramped up manufacturing of ammunition and drones since Russia’s invasion. Much harder to replace, experts said, are advanced American weapons, including air defenses.

Can U.S. weapons systems be replaced?

Russia has attacked Ukraine almost nightly since Putin’s forces invaded in February 2022, flooding the skies with missiles and drones, including dummy attack drones to exhaust Ukraine’s limited air defenses. In April, at least 57 people were killed in multiple strikes.

The death toll from the Russian attacks would “inevitably” be higher without the American Patriot air-defense missile systems protecting Ukraine’s skies, said Douglas Barrie, senior fellow for military aerospace at the International Institute for Strategic Studies in London.

The Patriots can track and intercept Russian missiles, including the hypersonic Kinzhal, which Putin has boasted was unstoppable. Kyiv uses them to protect critical infrastructure, including the country’s energy grid.

Earlier this month, Zelenskyy asked to buy 10 Patriots, a request Trump dismissed. “You don’t start a war against someone 20 times your size and then hope that people give you some missiles,” he said, a day after a Russian strike on the Ukrainian city of Sumy killed 35 people.

France and Italy have given Ukraine their Aster SAMP/T air-defense system but the issue is not “quality, it’s quantity,” Barrie said, pointing to the larger U.S. defense industrial base and greater U.S. stockpiles.

Although Trump criticized Putin over the weekend for his missile strikes and suggested imposing more sanctions on Russia, for Europe it remains a wait-and-see game.

The whiplash of Trump’s aggressive foreign policy means nothing is off the cards, experts said.

A worst-case scenario could see a ban on American weapons exports and transfers to Ukraine, which would bar European nations from buying U.S. weapons to give to Kyiv or transferring weapons with American components or software, Barrie said.

That could mean countries, including Germany, that have already given American Patriots to Ukraine would be prohibited from doing so. Such a move would seriously hamper Europe’s ability to support Kyiv and mark a fundamental shift in America’s relationship with its allies.

“It’s one thing for the U.S. to cease to be an ally, it is another for the U.S. to be an enemy,” Heisbourg said, noting that such a step could also damage the U.S. defense sector if weapons purchases were perceived to be unusable on Trump’s political order.

Filling the gap on intelligence sharing

In March, the Trump administration suspended intelligence sharing with Ukraine in a bid to force Zelenskyy to accept a truce with Russia. The about weeklong suspension impacted Ukraine’s ability to track and target Russian troops, tanks and ships.

There are certain capabilities, including “higher-end” surveillance and reconnaissance using satellites that “only the United States can provide,” said Matthew Kroenig, vice president of the Atlantic Council’s Scowcroft Center for Strategy and Security in Washington.

While the extent of intelligence sharing between the U.S. and Ukraine is not known, experts said it likely shows Kyiv near real-time buildup of Russian troop deployments and helps target long-range strikes.

Ukraine’s allies do not have as much satellite capability as the U.S. but could launch more, or Ukraine could use commercial systems if Trump cuts off intelligence again, experts said. The latter would likely have to come from a European provider — in March, the American satellite imagery company Maxar Technologies confirmed it temporarily suspended access to unclassified satellite images following the administration’s decision to pull intelligence sharing.

Ukraine also needs an alternative to Elon Musk’s satellite network Starlink, which is critical for Ukrainian defensive and civilian communications. European defense companies are discussing creating a satellite alliance but don’t currently have an alternative on the same scale.

Would Ukraine collapse without U.S. support?

If Trump walks away, or if Kyiv rejects a deal and keeps fighting with European support, it won’t necessarily mean “the collapse of Ukraine” although more people will almost certainly die if the U.S. pulls its air defenses and intelligence-sharing capabilities, Heisbourg said.

Trump has jolted European leaders into awareness that they need to take responsibility for their own defense, regardless of who occupies the White House, experts said.

That means European nations need to invest more in defense, work together to scale up military production and build trust to share intelligence.

“This issue is not a question about the next two months or the next two years. This issue is about the next two decades,” Gomart said.