U.S. President Donald Trump is accustomed to criticism from coast to coast - Democrats, disaffected Republicans, late-night comedians, massive protests. Yet in his second presidency, Trump’s most influential American critic doesn’t live in the country but at the Vatican.

It's an unprecedented situation, with the first American pope directly assailing the American president over the war in Iran, where a fragile ceasefire took hold this week. The announcement came after Pope Leo XIV declared that Trump's belligerence was "truly unacceptable.”

Never before has the relationship between Washington and the Vatican revolved around two Americans - specifically, a 79-year-old politician from Queens and a 70-year-old pontiff from Chicago. They come from the same generation and share some common cultural roots yet bring jarringly distinct approaches to their positions of vast power. And the relationship comes with risks for both sides.

"They’re two white guy boomers but they could not be any more different in their life experiences, in their values, in the way they have chosen to live those values,” said theology professor Natalia Imperatori-Lee of Fordham University. "This is a very stark contrast, and I think an inflection point for American Christianity.”