It was Americans (not Iraqis) who bore the responsibility under international law to provide security after Americans (not Iraqis) overthrew Saddam. It was we who failed.Colin Powell hit the nail on the head when he once uttered something along the lines of "if you break it, you own it." We invaded them and then did not provide adequate conditions for the country to reorganize, restructure, and eventually thrive.
What followed the "shock and awe" bombings? What plan was immediately initiated and put into action? Really none that anyone can recognize. Rumsfeld simply shrugged at the time and said shit happens during wartime.
Yes, we -- or more specifically Bush/Cheney/Rumsfeld -- failed, not the Iraqis.