Saddam Hussain was a convenient dictator. He ruled Iraq with an iron fist, and was quite content to kill many people and steal a great deal of assets and like all dictators he brought wealth and power to his cronies. For a while the Western democracies feted him and sold him weapons and bought his stolen oil, because he was a convenient safeguard for them against Iran.
However Saddam turned from an asset into a liability when Iraq invaded Kuwait. These things happen because dictators are unpredictable and become immersed in their own personality, believing their own propaganda.
Inevitably war followed but there was no plan about how to deal with Iraq after the war.
Today we see that having withdrawn from Iraq the USA will start bombing parts of Iraq in an effort to clear up some of the problems that have arisen as a direct result of the disposal of Saddam who from the grave now chants “Après moi, le deluge”.