You miss my point. Starting a war is not justified. Finishing it can be. Again, the line blurs if you are not directly under attack, but if, for example, the army of some North African warlord entered, say, Mali and started burning villages and slaughtering their inhabitants at random - would you not support the mobilisation of UN/NATO/independant forces to stop them? Would you prefer to sit and watch people kill who they want and take what they what they want unchecked?
Don't try to compare what I said to what Bush is doing. I did, after all, state that these days you've got to wait for the killing to start before you can take steps to stop it, otherwise you just look corrupt (which, in this case, I'm sure he is). There is a difference between invading to protect innocents who are under attack, and invading because you think they might soon be under attack. I thought I'd made that clear...
Let's make it something easier to imagine - You and a friend are ambushed in a dark alley at night. Are you going to stand there and watch your assailants kill your friend, or are you going to fight to save him? If you are that much of a pacifist that you wouldn't even condone violence in defence of yourself, your friends, or your family, then I just don't know what to say.