But they did disband the Iraqi army and the whole Iraqi state!
>"The fall of Baghdad saw the outbreak of regional, sectarian violence throughout the country, as Iraqi tribes and cities began to fight each other over old grudges."
These are things the Iraqi Army and Police could have kept under control, had they existed. Instead, unemployed soldiers made up much of the sectarian fighting forces.
A country without a state devolving into anarchy shouldn't be that surprising. But to the US, it apparently was!
[0] https://www.quora.com/If-Saddam-Hussein-and-Gaddafi-were-ous...
[1] http://edition.cnn.com/2000/WORLD/meast/10/30/iraq.un.euro.r...
Also, Sadam had outlived his utility.
There's also reporting about close ties between the Bush and Saudi families. Same private schools. Kids vacationed together.
The US got a lot of good will right after the invasion. It destroyed that by disbanding the Iraqi army, by failing achieve basic safety for the country and by managing the country in an incompetent fashion.
Moreover, the country was in horrific shape due to ten years of draconian sanctions. They were theoretically against Saddam but the average Iraqi suffered horribly - the looting of priceless Iraqi artifacts by destitute mob was an expression of what US sanctions had reduced the country to (along with Saddam himself, of course).
[0] https://www.theguardian.com/commentisfree/2012/feb/19/syria-...
I protested the Iraq invasion in 2003 but this is a revisionist and historically inaccurate version of why it failed so spectacularly.
The U.S. didn't occupy a functional country and then destroy it. The outbreak of mass murder and tit-for-tat violence wasn't motivated by political grievances against U.S. policy. The U.S. removed a dictator that was keeping the lid on religious sectarian infighting. It erupted immediately into a civil war and that was further inflamed by third parties.
"The fall of Baghdad saw the outbreak of regional, sectarian violence throughout the country, as Iraqi tribes and cities began to fight each other over old grudges. The Iraqi cities of Al-Kut and Nasiriyah launched attacks on each other immediately following the fall of Baghdad to establish dominance in the new country, and the U.S.-led Coalition quickly found themselves embroiled in a potential civil war. U.S.-led Coalition forces ordered the cities to cease hostilities immediately, explaining that Baghdad would remain the capital of the new Iraqi government. Nasiriyah responded favorably and quickly backed down; however, Al-Kut placed snipers on the main roadways into town, with orders that invading forces were not to enter the city. After several minor skirmishes, the snipers were removed, but tensions and violence between regional, city, tribal, and familial groups continued."
https://en.wikipedia.org/wiki/2003_invasion_of_Iraq