Asked by a reporter why the U.S. didn’t tell Japan or other allies about its decision to strike Iran before it did so, the president said: “We went in very hard and we didn’t tell anybody about it because we wanted surprise. Who knows better about surprise than Japan? OK, why didn’t you tell me about Pearl Harbor?”

“You believe in surprise, I think, much more than us,” Trump added, referencing the 1941 attack on the American fleet at Pearl Harbor in Hawaii that precipitated the United States’ entry into World War II.

For those just wanting the "joke".