History lesson
At the end of WWI, Iraq was carved out of the Ottoman Empire (initially it was the "British Mandate of Mesopotamia"). Whether by chance or by design, its borders roped in three warring factions -- the Shia, the Sunni and the Kurds -- which, again by chance or by design, made it a classic example of the British Empire's "divide and rule" theory, under which a region can be ruled by brute force with limited military resources because factions were too busy fighting each other to unite against the ruling party.

Saddam applied brute force to maintain a similance of order in Iraq. You could argue that only brute force can achieve this.

The U.S. is learning a lesson about 88 years too late -- Iraq can't be unified under anything less than an oppressive ruling party. It would be like populating California with nothing but Klansmen, Black Panthers and atheists and expecting them to cooperate and form a democracy.

Since when was the US trying to unify Iraq?