The NATO summit in Washington faces uncertainty with the potential return of Donald Trump to the U.S. presidency, raising concerns among American allies about defense spending and support. Trump's history of pressuring NATO members to meet spending commitments and his stance on Ukraine create apprehension among alliance leaders. Leaders like Canadian Prime Minister Justin Trudeau face criticism for insufficient defense spending, with Trump allies suggesting penalties for non-compliance. The summit also highlights the contrast between Trump's approach and President Biden's diplomatic efforts. Amid tensions, NATO leaders emphasize support for Ukraine and navigating complex geopolitical challenges.