This piece pointed to by Dave Winer and a few others is outstanding,  particularly the punch at the end:

So I put this on as a modest riposte to men with flags in their lapels who shoot missiles from the safety of Washington think tanks, or argue that sacrifice is good as long as they don’t have to make it, or approve of bribing governments to join the coalition of the willing (after they first stash the cash). I put it on to remind myself that not every patriot thinks we should do to the people of Baghdad what bin Laden did to us. The flag belongs to the country, not to the government. And it reminds me that it’s not un-American to think that war — except in self-defense — is a failure of moral imagination, political nerve, and diplomatic skill. Come to think of it, standing up to your government can mean standing up for your country.