“By siphoning off many of the hot-headed Islamists in the region, (and their money/resources), there are less hot-headed Islamists that are thinking about how swell it would be to take out the Sears Tower”
This “theory” was looked at and found seriously wanting in this thread
The war has probably damaged US national security. Let me repeat my post in errata's [thread](http://boards.straightdope.com/sdmb/showthread.php?threadid=205684) on the matter:
"No, the war has probably damaged American national security.
As you note if Iraq actually has any WMD the failure of the American troops to secure them means that the war has increased the chances that they fall in the hands of terrorists. This was, of course, the very thing the war was supposed to prevent.
In addition to this:
1)The war has cost the US one of its most valuable intelligence sources about Islamic terrorists: Syria.
- There have been reports of increased Al-quaeda recruiting and certainly there is great anger in the Arab world about the war.
3)The continuing deployments in horrible conditions in Iraq will erode troop morale and readiness and perhaps reduce recruitment in future years.
4)While it was focussed on Iraq the administration has let the situation in Afghanistan and North Korea drift. The latter is probably the most serious threat facing the US.
5)The war and its aftermath will probably end up costing 100-200 billion dollars. That is money that could have been used improving homeland security among other things.
6)The war has badly damaged American credibility and alienated public opinion in almost every single allied country.
I can barely see any plus side from the pov. of US national security to balance even one of these points let alone all of them. Sure Saddam was a brutal dictator but there is little reason to believe he was a significant threat to the US."