optic's primary argument against pacifism comes out of game theory, basically that if most are pacifists, the war monger has an advantage, because he is not bound by their scruples. He also feels that World War II and the Revolutionary War were justified. optic also has a big giant PHD-type brain, and if I'm in an argument with him, I'm unarmed by comparison.
I guess I shouldn't feel too bad, because pacifists have never definitively won the argument with those who advocate retaining the option of war. But...
I am not a pacifist because I argued myself into it. Since I don't read a lot of history, or political theory, or anything besides what I can skim off the internet. I'm not comprehensively informed, and I never have been. I may be better informed than a lot of Americans -- many of whom can't find their own home state on a map if it isn't labeled -- but I'm not an expert on anything, except perhaps cute tricks you can play with C++ templates programming and postwar science fiction.
What makes me a pacifist is one thing -- a lifelong revulsion for violence. I can't look at a war and see the honor and patriotism; I see the suffering of innocents. I always see a third path between surrender and war. I can't even watch violent movies without wincing every time someone is in pain. I can see an exception to the general rule of pacifism, where a war like World War II was a necessary defense of civilization. If I was motivated to read up on it, big brain guys like Bertrand Russell have written a lot on the topic, and I could borrow their ideas.
But it isn't that often that a Hitler or a Milošević comes along -- they are brilliant, charismatic sociopaths who were in the right place at the right time to seduce a country into barbarism. The most common case are wars that result from the shortsightedness, greed, and bloody-mindedness of the powerful.
Contrast that with the manifest success of non-violence. India, South Africa, the Civil Rights movement, the Velvet Revolution in Czechloslovakia, Solidarity in Poland ... the lesson of those struggles is that change can come from somewhere besides the barrel of a gun. It isn't always pretty, and the struggles are ongoing. But they prove that war isn't necessary. In fact they show that the most enduring, functional changes for the better since the second world war are not born of violence.
The opposite is true. I believe that Israel has a right to exist as a nation. But the ongoing troubles in the Middle East show a fatal flaw in Israel: they violently displaced the Arabs that have lived in Palestine for the millenea since the fall of the temple, and ever since the creation of Israel, they've been in a cycle of violence and brutality, punctuated occasionally by periods of relative calm. I'm no fan of Hammas or Hezbollah, but they exist because of how Israel was created.
This is similar to the problems the US created for itself -- Al Qaeda exists because of how America reacted to the Soviet invasion of Afghanistan. And before he became Bush's favorite bogeyman, Saddam Hussein was an ally of the United States. He was no less brutal when was our friend than he was as our enemy. The US supported dangerous violent people when it served our geopolitical aims, and now we're fighting them because we weren't able to control them. All of human history is an interlocking daisy chain of violence and retribution. Our own thoughtlessness and brutality reinfoces the thoughtlessness and brutality of our enemies. It's hard for me to see the US as a force for good when we're in the business of killing innocents.
I advocate the search for peaceful resolution of conflicts because I see no useful alternative. The costs of war are too high. The United States is in a war right now because of 9/11, which was horrific and unjustified, but we've already killed more non-combatants than Al Qaeda many times over. How has that made the world a better place?
But ultimately, for me it isn't a matter of argument or rhetoric, it's an emotional response, and faith in humanity. I feel that people can reasonably sit down and resolve difficult conflicts, if they keep talking. Can I justify this with a policy paper, or a mathematical proof? No. I can point to where non-violence has worked in the past, and how it might work in the future, but for me it's a matter of the heart.
If that makes me a Hippie-John Lennon Quaker pacifist, so be it.