http://maxspeak.org/gm/archives/00000402.html
The legitimate use of the term is as invective in response to obnoxious cheer-leaders for U.S. military action. It has nothing to do with anybody's right to an opinion on anything. The invective inhibits quite a few right-wing ideologues from claiming a monopoly franchise on patriotism or courage.
Of course making a substantive case against the war is a different exercise.
mbs
This "chickenhawk" critique is ridiculous and hypocritical, esp when coming from the left (and esp from those who've never worn the uniform themselves). What -- do you wish that W., Lott, Quayle, et al., had volunteered to kill Vietnamese? If they had, would you respect them more when they called for war on Iraq? Bush senior is a combat vet, and I don't recall anyone who opposed the first Gulf War saying that, well, at least he served.
There's plenty to critique in the current war cycle without going this simplistic route.
DP