I have some thoughts.
First, I am a veteran of the Iraq war and after spending several years of my life there I can say that I am fairly confident that nothing significant changed as a result. Some lives were saved and others were taken by my presence I'm sure but on the balance that altered nothing. By the end of my first tour (Later 2005) things had gone from a simmer to full blown genocide level violence. On the average day, we were finding hundreds of corpses of people killed by sectarian violence in Baghdad alone. That first tour shattered my world view and the belief that warfare could ever be anything other than an ugly business. By the end of my second, I was convinced that victory, as we had defined it at the time, was not achievable. The same goes for Afghanistan. At this point, it seems like the power players in Iraq are just waiting for us to leave to start up again and in Afghanistan, the last time I saw credible news on the subject, we could only claim to hold 3 provinces.
The entire notion that there is a polite or correct way to fight a war is silly enough. Warfare is nothing but cruelty. People who think otherwise are hopelessly naive. Even with cutting edge technology a 2,000 pound bomb is still sufficient to level a city block. Even with the best training, a soldier is just an armed man trying not to die and they will make mistakes. Does the fact that a reasonable mistake was made justify gunning down an innocent man in a car? I doubt the family of such a statistic would think so. The rules of warfare, in spite of what people might think, exist for one of two reasons. Either, they exist because the following such a rule makes it easier to achieve victory or they exist because some misguided fool thinks that there is a polite way to murder a large number of people.
There is a way to prosecute the war on terror, but it does not lie in striking out against our enemies with a massive show of military might. Such a method is suitable for bring ruin to a nation, not for halting the actions of a few thousand determined men spread across the world. I regret that I once thought invading Iraq was a noble endeavor. More than a million lives have been lost, millions more shattered and all so that I could feel a little safer at home. But I don't feel any safer. Worse still, I when I came back home, I realized that, were I in Mohammad Bin Insurgent's shoes, I probably would have done the same thing.
I hate that, by going to war, I realized just how ugly it was. I hate that, by going to war lent humanity to the enemy. And, I hate that by going to war, I realized that, were our roles reversed, I would hate the US in spite of the presumed nobility of the cause.