- We must do something
- This is something
- Therefore, we must do this.
After 9/11 the US had to do something, Afghanistan wasn't enough, so do Iraq.
The idea of 'doing something' about Iraq was a lot older.
9/11 was just the excuse. When you read about the subject it's interesting to realize how many people in Washington was against that war, including the Pentagon and the State Department, but powerful interest prevailed.
From https://www.haaretz.com/1.4764706:
"Is the Iraq war the great neoconservative war? It's the war the neoconservatives wanted, Friedman says. It's the war the neoconservatives marketed. Those people had an idea to sell when September 11 came, and they sold it. Oh boy, did they sell it. So this is not a war that the masses demanded. This is a war of an elite. Friedman laughs: I could give you the names of 25 people (all of whom are at this moment within a five-block radius of this office) who, if you had exiled them to a desert island a year and a half ago, the Iraq war would not have happened. Still, it's not all that simple, Friedman retracts [..]"
"Only a crisis - actual or perceived - produces real change. When that crisis occurs, the actions that are taken depend on the ideas that are lying around. That, I believe, is our basic function: to develop alternatives to existing policies, to keep them alive and available until the politically impossible becomes the politically inevitable."
Milton Friedman
Sept 2013: "Obama Seeks Approval by Congress for Strike in Syria"
https://www.nytimes.com/2013/09/01/world/middleeast/syria.ht...
We've got four star general - US Presidential candidate, and NATO Supreme Allied Commander right before 9/11 - Wesley Clark admitting it in public on YouTube. I'll never understand why the most important policy admission of the last 30 years is intentionally ignored in all discussion of what the West is doing in Iraq, Syria, Libya, et al. This is the Western powers - led by the US - looking to strip Russia's power out of the Middle East (or at least break it). According to Clark, particularly before China completes its rise to power (which would present a demand to dilute focus, weakening the ability to challenge Russia's strategic goals). These proxy conflicts haven't stopped for a single day since WW2. Don't take my word for it, or Clark's for that matter, just look at the powers in Syria wrestling over who gets to keep or acquire influence (the US/West v Russia).