Eventually I'll have more time to go into details, but points to ponder;
1) It helps to have a clear vision of what you want when the fighting is done. What results do you seek. I forget this early in the morning who said it; "The purpose of war is a better peace." Of course it complicates when someone attacks you and you are responding in defense, but still, strategy involves thinking and planning towards and end game and desired results come peacetime.
2) Like chess, many war/conflicts have an opening game, a mid game, and an end game.
3) It would appear the USA didn't have clear vision of Iraq after Saddam, and the Bath Party were gone, so we muddled the End Game. The Opening and Mid Games played well, except the Mid Game did plant seeds, or failed to remove "weeds" that resulted in the insurgency a year after Iraq was defeated and Saddam gone.
4) I've often thought we should have started off with massive carpet bombing ...
... of bags of pork rinds and pocket size USA Constitutions and Declaration of Independence with Arabic or Farsi on one page and the English on the other page.