REMEMBER AL QA QAA?

That's the Iraqi weapons depot that was looted because it was unguarded by Coalition forces. It was unguarded because THERE WEREN'T ENOUGH TROOPS. (If you follow the link, you'll see that it was an issue in the 2004 Presidential campaign.) The GAO has released a March 2007 report that finds:

According to knowledgeable DOD officials, field unit reports, lessons learned reports, and intelligence information, U.S. and coalition forces were unable to adequately secure conventional munitions storage sites in Iraq, resulting in widespread looting of munitions. These DOD sources indicated that U.S. and coalition forces were overwhelmed by the number and size of these sites, and DOD had insufficient troop levels to secure conventional munitions storage sites because of prewar planning priorities and certain assumptions that proved to be invalid. Despite war plan and intelligence estimates of large quantities of munitions in Iraq, knowledgeable DOD officials reported that DOD did not plan for or set up a program to centrally manage and destroy enemy munitions until August 2003, well after the completion of major combat operations in May 2003.

The costs of not securing these conventional munitions storage sites have been high, as explosives and ammunition from these sites used in the construction of IEDs that have killed and maimed people. Furthermore, estimates indicate such munitions are likely to continue to support terrorist attacks in the region.