What Lessons Should We Take From the Iraq War?

The biggest lesson to learn is that when you are planning a war, plan for the victory. In The Art of War by Sun Tzu, one of the imperatives is that you never disband a defeated Army, they are your best bet for security. I think another point is, be careful when getting involved in regime change. It didn't go well in Iraq, and as you can see, we learned nothing based on our actions in Libya and our intended actions in Syria. The devil you know.....