2020s American renouncement of allies

Since the second presidency of Donald Trump, the United States has adopted an isolationist  (America First) and expansionist foreign policy against multiple of its allies, mainly NATO and it's Indo-Pacific allies, triggering an unprecedented crisis. In December 2024, president-elect Donald Trump suggested that he might support withdrawal from NATO in light of low defense spending by America's European allies. During his election campaign, Trump said that European allies "treat us actually worse than our so-called enemies". Trump said he would not defend NATO allies in Europe if they did not meet the alliance's target of spending 2% of GDP on defense, and instead he would "encourage" Russia to "do whatever the hell they want".

During this time, the United States has threatened the sovereignty of two NATO-founding members, Canada and the Kingdom of Denmark.Trump's threats for the latter to concede Greenland to the United States, in particular, accelerated the deterioration of Euro-American relations, European efforts to rearm itself, and by extension, its relations with the majority of NATO countries.