“Donald Trump is the first president in modern history (who) did not start a new war.” PolitiFact's ruling: Mostly False Here's why: When President Donald Trump came into office, the U.S. was still struggling to extricate itself from wars in Afghanistan and Iraq that had begun more than a decade earlier. When he left, U.S. troop levels in both countries were sharply lower. And some of Trump’s supporters praised him for not starting any new wars. His son, Donald Trump Jr., tweeted Jan. 22 that "Donald Trump is the first president in modern history (who) did not start a new war."