Perhaps a reality check might be in order?
Sadaam, whom we are now told it would have been better to keep in power, prevented civil war by brutally enforcing the hegemony of the Sunni minority via genocide, torture, summary executions, chemical weapons and generally making the life of the Kurds and S h i' i tes a living hell. Every attempt at rebellion or even dissent was crushed in the most brutal fashion possible. To dissent meant not only being tortured and killed yourself, but seeing your family raped and killed prior to your own execution. If you did manage to escape Iraq, your relatives remaining behind would suffer in your place. So yes, a civil war was "prevented" but at an appalling cost.
After Saddam was removed from power, the Sunni terrorist groups in the country immediately began directing their attacks on the Shi'ites knowing that this would destabilize the nation and make consensus impossible. Their hope of course is to make Iraq ungovernable and force the coalition to withdraw, getting the infidels out of the Dar-El-Islam has always been priority one, and that includes the UN and any relief agencies. The Taliban followed the same policy of making it impossible for Westerners to work in the areas under their control, including agencies like the Red Cross.
Now, we are told that "we shouldn't even be in Iraq" because the problem was in Afghanistan. But most sane people realize that as soon as we leave Afghanistan, the current government will quickly collapse and the nation will once again descend into chaos and endless violence. The unlimited supply of new Taliban and Arab Jihadis who stream over the border from Pakistan, and the almost unlimited funding they receive from Petrodollars, will make that inevitable. Even if we had nabbed Bin Laden or made him a martyr, countless other Bin Ladens are awaiting their turn to be the next contenders.
Our stated way of dealing with the problem of Jihad, is to attempt to kill or imprison (and then eventually release) all the active Jihadis, we've been following that approach for decades now, while simultaneously playing Mr. Nice Guy with the forces that produce them. So we kill the members of the terror cell, but we tolerate or encourage the Mosque that encouraged them, the Madrassa that trained them, the Imams that spurred them on, the literature they read, and the countries giving them the money they spent.
Aside from the fact that that approach will never work, it commits us to a "forever war" of attrition. And do we really think we are willing to spend lives for as long as the Jihadis?
But if stamping on them one by one is the best we can come up with, then we'd better stay in Iraq for as long as possible if only to provide a convenient sand-box to which we might attract the newest crops of Jihadis and then kill or capture them. Once we leave, we are back to trying to do that on our own territory, not theirs. And lets face it, once we leave the Dar-El-Islam, and they are able to concentrate on attacking us at home, sooner or later they will pull off an attrocity in the USA of such scale that nothing but massive retaliation will satisfy the public, and which nation are we going to retaliate against?
Edit: Skuzzy is there anyway to modify the board "auto-censor" so we can use the word S h i i t e?