I think I've mentioned here that Rumsfeld had some good reasons for not wanting to send 500k troops to Iraq:
1) It would make the occupation footprint on the strongly nationalistic Iraqis even heavier.
2) It makes the supply lines heavier and more expensive, requires more troops to protect them, and requires even more planning, coordination, etc.
Unfortunately, when the invasion stopped going according to plan early on, [link|http://www.theledger.com/apps/pbcs.dll/article?AID=/20060313/ZNYT03/603130408|he refused to modify his plans]:
The dispute, related by military officers in interviews, had lasting consequences. The unexpected tenacity of the Fedayeen in the battles for Nasiriya, Samawa, Najaf and other towns on the road to Baghdad was an early indication that the adversary was not merely Saddam Hussein's vaunted Republican Guard.
The paramilitary Fedayeen were numerous, well-armed, dispersed throughout the country, and seemingly determined to fight to the death. But while many officers in the field assessed the Fedayeen as a dogged foe, General Franks and Defense Secretary Donald H. Rumsfeld saw them as little more than speed bumps on the way to Baghdad. Three years later, Iraq has yet to be subdued. Many of the issues that have haunted the Bush administration about the war the failure to foresee a potential insurgency and to send sufficient troops to stabilize the country after Saddam Hussein's government was toppled were foreshadowed early in the conflict. How some of the crucial decisions were made, the behind-the-scenes debate about them and early cautions about a sustained threat have not been previously known.
* A United States Marines intelligence officer warned after the bloody battle at Nasiriya, the first major fight of the war, that the Fedayeen would continue to mount attacks after the fall of Baghdad since many of the enemy fighters were being bypassed in the race to the capital.
* In an extraordinary improvisation, Ahmad Chalabi, the Iraqi exile leader who was a Pentagon favorite, was flown to southern Iraq with hundreds of his fighters as General Franks's command sought to put an "Iraqi face" on the invasion; the plan was set in motion without the knowledge of top administration officials, including Secretary of State Colin L. Powell and George J. Tenet, the director of central intelligence.
* Instead of sending additional troops to impose order after the fall of Baghdad, Mr. Rumsfeld and General Franks canceled the deployment of the First Cavalry Division;
General McKiernan was unhappy with the decision, which was made at a time when ground forces were needed to deal with the chaos in Iraq.
[...]
Maybe Rumsfeld will ultimately be proven right and the Iraqis will stand up and take things into their own hands in a way that wouldn't happen if there were there were 3 times as many foreign troops there. We'll never know; but we will know that Rumsfeld was wrong if Iraq devolves into chaos or splits up violently. It's hard to imagine, though, that the situation in Iraq would be less secure if there were enough high-quality troops and police in place to prevent the high levels of murders, kidnappings, etc., that are happening there now.
It doesn't take much to make an [link|http://en.wikipedia.org/wiki/IED|IED]. While they haven't found 250,000 tons of explosives in this operation, every cache they do find helps. So maybe "a bunch" is the wrong word - I won't argue with you about that. :-)
Cheers,
Scott.