NATO's 75th anniversary summit was meant to showcase the triumph of a larger, stronger alliance. Instead, leaders are coming together in Washington in the shadow of setbacks in Ukraine and electoral headwinds on both sides of the Atlantic.

U.S. President Joe Biden, fighting for his political life after a disastrous debate against NATO skeptic Donald Trump, will turn his attention away from campaigning to welcome leaders of the 32-nation trans-Atlantic alliance for three days from Tuesday.

Biden has also invited the leaders of Australia, Japan, New Zealand and South Korea, a sign of NATO's growing role in Asia in the face of a rising China.