American and British armed forces will likely soon begin to disarm Iraq by destroying the regime of Saddam Hussein. We do not know whether they will have the explicit authorization of veto-wielding members of the United Nations Security Council. But either way, the men and women ordered to undertake this mission can take pride in the justice of their cause. Critics argue that the military destruction of Saddam Hussein's regime would be, in a word, unjust. This opposition has coalesced around a set of principles of "just war" — principles that they feel would be violated if the United States...