I've taken to listening to podcasts while I drive and my affection for Victor Davius Hanson led me to this one where he debates Ronald Edsforth of Dartmouth on the topic, "Is Preemptive War in order to Promote a Free Society Justified?" It's worth listening to the whole thing just to understand the peace activists intellectual foundation.
The chief component of that foundation, as articulated by Mr. Edsforth, is the concept that war is the worst thing in the world. The claim is that war turns a young generation into murderers and torturers. While it is indeed true that violence against other humans is extolled on the battlefield, it is not true that war creates the most hideous versions of humanity. This is illustrated by this little snippet from Victor Davis Hanson.
(I can't figure out where I can host mp3 files with an embeddable player, so I had to make a video and host it on YouTube.)
Imagine the morally corrosive effects of pacifism on the Dutch soldiers to be told to plug their ears so they didn't have to hear the screams of the dying. That kind of thing happened on a national scale in Mao's China, Stalin's Russia, Hitler's Germany and Hussein's Iraq. It went on for years. In all cases, children were taught in school to recognize signs of disloyalty to the regime in their parents and turn them in if they were detected. Everyone learned to spy on everyone else because they knew what was going on all around them - the torture, the murder, the rape rooms - and they were willing to allow their neighbors to be devoured if it meant that they would be saved.
That is a far worse version of humanity than the men and women who serve in the military and are molded by war. This relatively tiny and even comparatively benign example from VDH utterly demolishes the basic premise of the peace activists.