What is NATO? Calls for US exit spark debate over alliance’s future

LOS ANGELES - A growing number of Republican lawmakers are advocating for the United States to leave NATO, with figures like Sen. Mike Lee (R-UT) and Rep. Thomas Massie (R-KY) publicly questioning the alliance’s relevance. 

The push, dubbed "AmerExit", comes as US-Ukraine relations remain tense, following stalled peace talks and Trump’s decision to cut military aid to Ukraine.

Lee, in a series of posts on X (formerly Twitter), argued that NATO is moving on without the US, and suggested it’s time for the US to "move on from NATO." Rep. Massie echoed these sentiments, calling NATO a "Cold War relic" that should be phased out.

The debate escalated when Elon Musk, who now leads the Department of Government Efficiency (DOGE) under the Trump administration, expressed support for a US withdrawal, agreeing with a post stating that NATO no longer benefits the country.

What is NATO, and why was it created?

The backstory:

The North Atlantic Treaty Organization (NATO) was founded on April 4, 1949, as a political and military alliance to counter the Soviet Union’s influence in Europe. Its original 12 members included the US, Canada, and several Western European nations, committed to mutual defense under Article 5, which states that an attack on one member is an attack on all.

Since the end of the Cold War, NATO has expanded to 32 countries, with Finland and Sweden joining most recently amid concerns over Russia’s aggression in Ukraine.

How does NATO operate today?

What we know:

NATO’s primary mission is to defend its member states and ensure European security, particularly in response to threats from Russia and other adversaries. The alliance operates on a collective defense principle, where an attack on one member is considered an attack on all.

The United States is NATO’s largest financial contributor, covering more than 50% of the alliance’s total budget. In 2023, the US spent 3.3% of its GDP on defense, amounting to approximately $880 billion. 

This significant investment has allowed NATO to expand military operations, strengthen its eastern flank, and deploy troops and equipment near Russia and Ukraine as tensions rise.

What we don't know:

Despite NATO’s ongoing operations, uncertainty remains about how the alliance will respond if the US moves toward withdrawing. 

With the Trump administration reviewing aid to Ukraine, questions arise about whether this will result in a permanent shift in US-NATO relations. Additionally, if the US reduces its financial contributions, it is unclear how other NATO members, particularly Germany, France, and the UK, will adjust to cover potential funding gaps.

Would the US withdrawal from NATO be legal?

The other side:

Despite calls from some lawmakers, withdrawing from NATO is not a simple process. Under the 2024 National Defense Authorization Act (NDAA), the president cannot unilaterally withdraw from the alliance without Congressional approval. The law requires either:

• A two-thirds majority approval in the Senate, or
• A separate act of Congress to authorize the withdrawal.

Legal scholars suggest that if the executive branch attempted to exit NATO without Congressional approval, it would likely face a legal challenge. 

The dispute could escalate to the Supreme Court, where justices would have to determine whether the president has the authority to override Congress on treaty obligations. 

However, it remains unclear who would have legal standing to challenge such a move, though service members, NATO-allied nations, or property owners with ties to NATO operations could potentially bring a case.

What do Americans think about NATO?

By the numbers:

A 2024 Pew Research Center poll found that 58% of Americans hold a favorable opinion of NATO. However, this number declined by four percentage points from the previous year, reflecting a growing partisan divide over the alliance’s role.

What's next:

While some Republican lawmakers and Musk advocate for an NATO exit, Defense Secretary Pete Hegseth has urged European allies to increase defense spending instead of relying so heavily on US funding.

Trump has not publicly committed to withdrawing from NATO, but his administration’s halted aid to Ukraine and calls for NATO reform indicate that changes in US policy toward the alliance may be coming.