In his first term President Trump episodically threatened to pull out of NATO, removing the United States as the linchpin of the most successful military alliance in modern times. In his second term, he is trying a different approach: hollowing it out from within.
Mr. Trump’s decision to reverse three years of unity in aiding Ukraine against Russia’s invasion and open negotiations with President Vladimir V. Putin has forced NATO leaders to confront a fundamental question: If Mr. Putin decided to pick off a member of the alliance, is there any reason to assume Mr. Trump would come to that country’s defense, the key to its strength?
“We have to assume not,” a senior member of the German government said at the Munich Security Conference, declining to speak on the record because of the huge sensitivity of his conclusion. In one short month as president, he and others contended, Mr. Trump has undercut the trust that sits at the center of the 75-year-old defense pact, that an attack on one member of the alliance would bring a response by all, led by the United States.
That fear has only accelerated in the past day, since Mr. Trump began echoing Mr. Putin’s talking points, falsely accusing Ukraine of provoking the invasion of its own territory and casting Russia as the aggrieved party rather than the aggressor. It is a rewriting of modern history that has left the NATO allies stunned and questioning the viability of an alliance with Washington at the center.
European officials knew when Mr. Trump was elected that the fundamental precepts of the post-World War II order would be threatened. They had been alarmed during the campaign when he said he would “encourage” the Russians “to do whatever the hell they want” to NATO members that did not contribute enough, in his view, to the alliance. They knew that even if the United States remained, on paper, the nuclear-armed behemoth at the center of NATO, Mr. Trump’s public musings could corrode the institution from within and undercut the goal of the alliance created in 1949 to confront the Soviet Union.
But the speed at which it has all unraveled has created a crisis of enormous proportions, at a time when European leadership is weak. Mr. Trump’s decision to impose tariffs, making no distinction between allies and adversaries, seemed harmful but manageable.