No kidding! This "justification" for "war" is sounding like a broken record.
Wasting money to kill others (who disagree with you) is spiritually retarded.
When are people going to demand that violence is NOT the solution -- it is precisely part of the problem in the first place!
The trouble with that sort of thinking is that it fails to account for the fact that peace requires participation by everyone, whereas war can be started unilaterally. Hitler, for example, actively wanted war, and was frustrated by repeated capitulation to his outrageous and growing demands. We all know how that turned out in the end, of course, but it was a long painful trip for everyone involved.
The other related question- In the face of a belligerent, are you willing to give up everything to maintain a pretense of peace? Is there nothing you wouldn't surrender in order to avoid raising a fist in defense of property, of principal, or of a person?
And even if you would bare your neck to preserve the peace, and gladly be felled for your sense of 'spiritual intellegence', would you sacrifice your family, friends and neighbors for the same?
If somebody wanted to rape your sister/wife/daughter, and it was in your power, but not hers, to stop him, would you let the offense proceed and pat yourself on the back for your restraint?
War between nation-states is often merely an expansion of these scenarios.
The only counter argument I can see to my line of thinking is the notion that you can cure the evil in human hearts with enough love. I know of no basis in the history of human events for this naivety.