“We are not sort of having a discussion in very quiet times where there is a guy in the White House who’s not a strong believer in alliances and in old-fashioned NATO,” Grande said. “We have a war in Europe. We have a serious concern for many Europeans that the confrontation with Russia might escalate in some shape or form, and then where are we?”

Trump repeatedly criticized NATO allies during his first term for not meeting defense spending targets, openly suggesting reduced U.S. support and even hinting at withdrawal. At a rally this year, he recalled telling allies, “If we don’t pay, are you still going to protect us? … Absolutely not.”

Trump hasn’t said publicly that he would pull out of NATO, but reportedly has discussed it repeatedly in private. He did say on the campaign trail that he would “encourage” Russia “to do whatever the hell they want” to NATO allies who don’t spend enough on defense.

Trump told European Commission President Ursula von der Leyen in 2020 that the U.S. wouldn’t come to Europe’s defense if it was attacked, POLITICO reported. He has said NATO countries subsequently spent “billions and billions” of dollars on their defenses in the wake of his threat.

While critics argue the strong rhetoric is undermining the alliance, some Republicans view it as effective pressure that prompted NATO members to increase military funding.

Both Trump and pro-NATO advocates stress the need for allies to meet defense spending targets, but Trump has at times framed it as a condition for U.S. support. Those allies appear to be relying on the law to bar Trump from taking extreme measures.

“Congress passed legislation according to which you cannot leave NATO without the consent of Congress,” former NATO Secretary General Anders Fogh Rasmussen said in an interview on Wednesday. “And during my visit to U.S. Congress, I have seen a very strong bipartisan support for NATO, staying in NATO. Obviously, a U.S. president can, as a commander in chief, make life difficult for NATO, but to see the U.S. leave NATO? No.”