An acoustic version of "Smooth Operator” blared from loudspeakers as foreign ministers, commerce officials and business executives sipped Negroni cocktails by the pool of a swanky golf club. At the elite Asia-Pacific Economic Cooperation gathering in Lima, there was only one big topic of conversation: Donald Trump.

Diplomats swapped tips (and horror stories) on dealing with the incoming U.S. president. The last thing you want is him tweeting about an issue you’re working on because then it’s game over, one said. Remember, he holds a grudge, another warned.

Trump’s return didn’t catch APEC attendees off guard — preparations for his possible re-election had been going on for months — but that hasn’t made the prospect of his second term any easier. At a cocktail event in the Peruvian capital for the forum’s VIPs, there was a sense of existential angst in the air.