Brian Becker reviews the history of heated debate within the socialist  movement over the necessity of taking a principled, anti-imperialist position in opposition to the U.S. war machine. Almost 18 years ago, George W. Bush launched the invasion of Iraq, a conflict that would ultimately take the lives of over a  million Iraqis. Whether and how to oppose this war -- and others like the 1991 Gulf War or the 2011 war on Libya --  has been a persistent topic of debate.