The open feud between President Donald Trump and Pope Leo XIV has plunged the country into a novel phenomenon, marking a new low for the Vatican’s relationship with the United States.

There are many firsts of the Trump-Leo feud. It features the first American pope, born in Chicago; the U.S.’s first Catholic vice president, JD Vance, who backed Trump against the Vatican on Tuesday, despite tying his faith to his political identity and writing a book about his conversion to Catholicism; and the Iran war, which sparked the largest disruption to the global energy supply in history.