For years, President Donald Trump has had a complicated relationship with the North Atlantic Treaty Organization (NATO). His latest comments about the alliance, made during a meeting in the Oval Office, have sparked renewed debate over the future of the military alliance and the US’s role in it.

On Thursday, March 6, Trump expressed uncertainty about whether NATO would come to America’s defense if the country were attacked—despite the fact that NATO has already done so, and in the most significant instance possible, after the September 11 attacks.

This comment isn’t entirely new. Trump has long been vocal about his dissatisfaction with NATO, accusing member countries of not pulling their weight when it comes to defense spending.

The US, he argues, spends far too much on the alliance, while other members fail to meet agreed-upon defense spending targets. It’s a perspective that has shaped his approach to international relations throughout his time in office and even into his post-presidency.

Trump’s remarks came at a particularly sensitive time.

The US president’s relationship with Russian President Vladimir Putin has been a topic of considerable scrutiny, with many questioning whether Trump’s friendly demeanor towards Putin poses a risk to NATO’s cohesion.

Meanwhile, as the war in Ukraine rages on, Trump’s insistence on prioritizing military spending targets for NATO countries raises alarms about the future of US support for Europe, especially if nations fall short of meeting their defense commitments.

The NATO Defense Guarantee: A History of Loyalty

In the past, NATO’s Article 5, which guarantees mutual defense, has proven its value.