“The War in Iraq — I was the one that said, ‘Don’t go, don’t do it, you’re going to destabilize the Middle East,’ ” Trump said. “So I’m not one with a trigger.”
Trump’s statement rates Mostly False.

We only found one example of Trump commenting on the Iraq War before the invasion, and he seemed apprehensive but not vehemently opposed to the operation. He only started publicly denouncing the war after it started.

Trump makes it sound like he stood on a railroad to try to stop the Iraq War train in its tracks. In reality, by the time he got around to forcefully criticizing the war, that train had already left the station.