The prospect of a second US presidency for Donald Trump, and what that means for the defense of Ukraine against Russian aggression is hanging over a major gathering of European leaders on the other side of the Atlantic.

Trump — who’s been at best lukewarm in his commitment to European defense — leads US President Joe Biden in polling ahead of November’s US election, and did little to allay European concerns by naming JD Vance as his running mate. Vance told Bloomberg earlier this week that while Russia’s war in Ukraine is “tragic,” the US “doesn’t have the interest to respond to every tragedy that exists in the world.”