We should de-escalate the war in Iraq because all the reasons we were told for the war (except getting Saddam) turned out to be lies.
The neocons will say, "He gassed is own people, mass graves, if it was up to you he would still be in power, etc".
We should de-escalate the war in Iraq because too many soldiers are dying and more will die in the weeks and months ahead.
The neocons will say, "We will escalate and regain control, submit or die Iraqi, blah, blah, blah)
We should de-escalate the war in Iraq because the war is costing too much for too little gained.
The neocons will say, "We will pay any price, bear any burden for the causes of freedom and democracy, blah, blah, blah)
We should de-escalate the war in Iraq because war is immoral and the wrong way to accomplish foreign policy objectives.
True but, many people in American don't believe this, convincing them would require a "change of heart" which takes a long time.
This would first require educating people so that they understand what is occurring and why it is occurring. Then it would require helping them realize that they were supporting a policy most Americans do not agree with.
Illegitimate is the best umbrella that all the other reasons can stand under, the framework that protects them all, giving them validity. Once the American people realize the war is imperialism and all the prior stated reasons were merely excuses and illusions, they will withdraw overall support. They will not support a war this costly for the illegitimate goal of controlling another country's resources.
The reason why they won't define their goals or their plans for leaving are simple - it would cause too much political turmoil.
To know their goals you must look at their achievements to date, what they are doing now, and project from there. This leads most rational people to seeing imperialism.
To find out when they plan to leave the answer is they don't plan to. They have publicly stated they will be there through at least 2006, ask them again then.
We need to measure progress in the control we relinquish to other responsible parties, not in the control we gain by escalation of this war.