Acting on impulse is characteristic of President Donald Trump, and his recent threat on April 1 to pull the United States out of the North Atlantic Treaty Organization (NATO) may be another example. But legally and politically, withdrawing is far from straightforward.
Legislation enacted under President Joe Biden and included in the National Defense Authorization Act (NDAA) 2024 limits the president’s ability to exit NATO without Congressional approval. The NDAA also says a Senate two‑thirds vote would be required if a withdrawal were pursued, making such a move a steep uphill battle given current Senate math and Trump’s political standing. Congress could alternatively pass a statute authorizing or blocking withdrawal, and any dispute could ultimately end up in the courts.
Throughout his second term, Trump has criticized NATO, calling members “freeloaders” and “paper tigers.” His anger over perceived lack of European support for U.S.-Israel military action in Iran and concerns about Iranian influence in the Strait of Hormuz appear to have intensified his rhetoric. European NATO members say they were not consulted on the Iran action and note the U.S. was not directly attacked, so they saw limited reason to join.
Tensions with allies have surfaced before — for example, Trump’s past interest in acquiring Greenland alarmed other NATO members. Historically, though, European allies provided extensive support to the U.S. in operations like the war in Afghanistan.
Founded in 1949 after World War II, NATO has long been a central deterrent to Soviet, and later Russian, influence in Europe. A U.S. withdrawal would be logistically complex because of the extensive U.S. military presence and infrastructure across Europe and the U.S. role in the nuclear deterrent that underpins allied security.
If American commitment weakened, NATO’s credibility could erode, potentially increasing Russian and Chinese influence in Europe and prompting major European powers such as the UK, France, and Germany to strengthen their own militaries.
