"The Final Straw" by R.E.M.

"That's The News" by Merle Haggard (who wrote pro-Vietnam war songs like "The Fightin' Side of Me" back in that era)

"Homeland Security" by Tom Paxton - more about civil liberties infringements here at home than the Iraq war, but contains the following verse:

We've looked all over Baghdad,
We've looked all over Iraq,
For some kind of terrible weapons
Just right for a sneak attack.
We've turned the whole place upside down,
We've done all we can do.
Now the Army, the Navy and old Tom Ridge
Have decided to pick on you.