Anyone who has ever studied the history of American diplomacy, especially military diplomacy, knows that you might start in a war with certain things on your mind as a purpose of what you are doing, but in the end, you found yourself fighting for entirely different things that you had never thought of before … In other words, war has a momentum of its own and it carries you away from all thoughtful intentions when you get into it. Today, if we went into Iraq, like the president would like us to do, you know where you begin. You never know where you are going to end.

As quoted in "George Kennan Speaks Out About Iraq" at History News Network (26 September 2002)