Trump can decide not to defend NATO members

Analysts and diplomats say that the NATO alliance created in the Cold War that has long served as the basic fabric of European ​security is fraying and the mutual defense agreement at its core is no longer taken as a given. That reality is sinking in for Europeans, who have counted on NATO as a ⁠bulwark against an increasingly assertive Russia.

As recently as February, NATO Secretary-General Mark Rutte had dismissed the idea of Europe defending itself without the U.S. as a “silly thought.” Now, many officials and diplomats consider it the default expectation. NATO has been challenged before, not least during Trump’s first term from 2017 to 2021, when he also considered withdrawing from the alliance. But while many European officials until recently believed that Trump could be kept on board with pomp and flattery, fewer now hold that belief.

Legally, Trump may lack the authority to withdraw from NATO. Under a law passed in 2023, a U.S. president cannot exit the alliance without the consent of two-thirds of the U.S. Senate, a nearly impossible threshold. But analysts say that, as commander-in-chief, Trump can decide whether the U.S. military will defend ​NATO members. Declining to do so could imperil the alliance without a formal withdrawal.

Analysts say European nations have good reason to keep the U.S. engaged in NATO despite doubts over whether Trump would come to their defense. ⁠Among other reasons, the ​U.S. military provides a range of capabilities NATO can’t easily replace, such as satellite intelligence. Even if Trump and the Europeans find a way to stay together in NATO, ​diplomats, analysts and officials say, the transatlantic alliance that has been central to the global order since World War Two may never be the same.