Anybody who is living right now should have realized that
(a) War is miserable - especially for people that are being bombed.
(b) A significant proportion of current wartime death is being brought about by America's military misadventures in Iraq, Afghanistan and now (alas) Pakistan.
Professors are supposed to be smart. They should be the first to understand this point. Especially professors who began their learning career elsewhere - say at some IIT in India. This is because (a) they are smarter than the average human being (by mere virtue of them being professors) (b) They are not subjected to the patriotic propaganda that Americans have been subject to.
So there's essentially two possibilities.
One. Maybe there is not anything unethical with killing millions of innocent people in war (I kid you not, the Iraq death toll alone exceeds a million) in order to achieve ill-defined goals. Maybe I've been wrong all along. Maybe there's something to be said for the Limbaugh-Bolton-Cheney worldview which I have not been able to fathom. Maybe these smart professors know something that I don't.
Two. Maybe the professors are doing what is best for their career, treating money from the military as they would money from other sources. Their families won't feed themselves after all. Since the money only implicitly tainted, most people won't know the difference. And since this taint is that implicit, it's nothing that going to a church/temple/mosque won't solve.
I don't have anything against the poor joining the military in the US. They're doing this because they are convinced that they're doing the right thing for god and country. They are doing this because they are convinced that the other side is evil. Military recruits in the US (much like anywhere else) are overwhelmingly lower middle class. They are doing this for opportunity - and also because they been subjected to propaganda from the get-go. I'm not judging these people who are convinced they're doing the right thing. They are brave enough to put their lives on the line for a cause they believe in. They are more victim than oppressor. I am also willing to give professors who were educated entirely in the US the benefit of the doubt.
But professors who underwent a significant amount of education beyond the US borders are a different story. They have a choice to take a conscientious stand. Some refuse to work on military projects. A tip of my hat to them. But some sell their souls and participate in the mass goring of people elsewhere. And in my book, they rank lower than GS employees.