First let's be clear. The insurgency in Iraq is killing more Iraqis and fewer Americans. Despite this, polls now indicate that a majority of Americans want to get out of Iraq. The insurgent leaders take note of our media and know our poll results. They now know what they have always thought: what counts in defeating the fledgling Iraqi democracy is the number of bombs they set off. Even if they mostly kill Iraqis and alienate the Iraqi people, the bombings weaken the will of America to do what it takes to support the new government. If the insurgents just keep bombing, the Americans will simply give up and go away.
What happens then? Unlike Vietnam, there is no army ready to invade Iraq the way the North Vietnamese Regular Army invaded South Vietnam after the Americans abandoned it, and refused even to supply the South Vietnamese Army with the spare parts they needed to keep their weapons working. Or is there? Iran is investing in Iraq, supplying funds and clergy to set up schools in the Shi'ite areas. Perhaps Iran has designs on Iraq. Or perhaps the insurgents hope to bring back the Baathists (Saddam Hussein's party, which blended Nazi ideology with pan-Arabism).
Either way, if Americans walk away from the Iraqi democracy before it can stand on its own, Americans will have nullified the sacrifices of American troops and their families, and betrayed the Iraqi people yet again. And instead of a democratic Iraq as the nucleus of an Islamic Enlightenment whose ideas and ideology could defeat the Global Salafist Jihad, we will have another failed state providing the Jihad with a new base of operations.
Americans will also have given up a valuable distraction. You see, if Iraq is dividing our forces in the Global War on Terror (GWOT), it is also dividing the forces of the terrorists. All those jihaddicts in Iraq are not in Afghanistan. Further, all the press about Iraq "sucks the oxygen" out of stories on Afghanistan. Whatever the jihaddicts do in Afghanistan gets no traction in the West because of Iraq. Essentially, Iraq is providing the cover Afghanistan needs as it transitions to a post-war state.
So, whether or not we moved with too much or too little haste in deposing Saddam, I think we should stay our course and leave Iraq when the Iraqi people, through their government, tell us to go, and not a moment sooner.
Because, Iraq or no Iraq, we are going to be confronting global Islamist insurgency until the insurgency burns itself out. I'd rather we do it in Iraq than in America and Europe (which is acting in its own self-interest by freeloading off the American effort in Iraq). And I'd rather that those who do not want to oppose it with violence oppose it with nonviolence instead of appeasing it or just giving in.