Europe Is Left with Hard Choices as Trump Sours on Ukraine

European leaders have dealt with President Trump’s return to office by trying to keep him cooperating on Ukraine while pushing to ramp up their own defense spending so they are less reliant on an increasingly fickle America.

But Friday’s meeting in the Oval Office, in which Mr. Trump berated President Volodymyr Zelensky of Ukraine, underscored for European leaders that they might need to come up with more concrete plans — and fast.

Following the heated exchange, a visibly annoyed Mr. Trump canceled a news conference with the Ukrainian leader and posted on social media that Mr. Zelensky was “not ready for peace” so long as he has American backing.

His anger — and his threat that the United States could stop supporting Ukraine if it did not accept any U.S.-brokered peace deal — was just the latest sign that Mr. Trump was pivoting American foreign policy away from traditional allies in Europe and toward Russia.

“The scene at the White House yesterday took my breath away,” Germany’s president, Frank-Walter Steinmeier, told D.P.A., a German news agency, on Saturday. “I would never have believed that we would ever have to defend Ukraine from the United States.”

The stark shift in American strategy has left the continent’s leaders reeling. Many worry that if the war ends with a weak deal for Ukraine, it would embolden Russia, making it a greater threat to the rest of Europe. And the change in tone makes achieving greater self-reliance more urgent than ever, even if the European leaders face the same daunting challenges as before.