Fight for what? What was the goal of these invasions? These were wars without reason behind them. It was predictable that we would end up in a long guerilla war with no good outcome. Invading Afghanistan and Iraq were the dumbest military blunders since Custer decided it might be fun to pimp with a few Indians.
That was a worthy goal.
This mistake was not that we attacked Iraq, it's that we did it half ass with both hands tied behind our backs when we could of just bombed them back to the stone age from 30,000 feet without loosing a single soldier.
In fact, if we had just nuked Fallujah when they were cutting off peoples heads hanging the dead bodies of Americans from bridges the war would have been over instantly, saving us billions of dollars and over 4,000 US soldiers lives. Heck the rag heads would of been lining up to surrender in lines 100 miles long once they knew we were serious.