Of all five living presidents, none was closer to ground zero on 9/11 than Donald J. Trump. Yet on the 25th anniversary, he will be 200 miles away at the Pentagon while Bill Clinton, George W.

Bush, Barack Obama and Joseph R. Biden Jr. gather in New York. The split reflects a nation that has moved past the war on terrorism that once dominated politics.

Domestic threats — from the Jan. 6 Capitol assault to the assassination of Charlie Kirk and antisemitic attacks — now eclipse foreign ones. Mr. Trump has redefined terrorism to include drug cartels and left-wing extremism while downplaying right-wing violence. "You don't hear President Trump talk about terrorism all that much unless they're attaching it to issues at the border," said Nick Rasmussen, former director of the National Counterterrorism Center who served under four presidents and now leads the McCain Institute. He warns of "hollowing out of our institutions" from cuts and reorganizations. Daniel Byman of the Center for Strategic and International Studies says counterterrorism no longer drives the presidential agenda.

Bruce Hoffman, a Georgetown scholar of five decades, cautions: "When people ask me, are we safer today, my answer is no." The distance from ground zero mirrors a country that has turned the page, even as experts question the cost of complacency.