As NATO celebrates its 75th anniversary with a summit in Washington this week, the alliance is facing some familiar foes and challenges: Russia's war on Ukraine is ongoing, Moscow's alliances with China, North Korea and Iran are strong, and the military coalition's defense spending remains a perennial bugbear among members. Another familiar, yet unpredictable, challenge lies ahead: the possibility of another U.S. administration led by former President and Republican candidate Donald Trump. Trump had a tense and combative relationship with the military alliance during his last term in office over 2017-2021, lambasting other member states for not honoring their 2014 commitment to spend 2% of their national GDP on defense spending. While campaigning to return to office in the