1. WWII ended in Europe in 1945 - and we have maintained combat troops there for the past 65 years and peace has been maintained.
2. WWII ended in the Pacific in 1945 - and we have maintained combat troops in Japan and Twain for 65 years keeping the peace.
3. The Korean War ended in 1953 - and we have maintained combat troops in South Korea for 53 years keeping the peace.
All of this to the betterment of the areas affected and of our own nation.
In 2010 we pull combat troops out of Iraq. Is peace possible without them??
In Europe, there was a shared system of heritage, values and religion.
In Japan, there was an united ethnic population, with a strong tradition of central government and submission to authority.
In Korea, we had no choice. There was only a truce, not a peace treaty. Plus, South Korea's capital city was less than a day's march from the DMZ. And, for all of these reasons, we had a government and population totally behind us.
I don't mean to suggest the withdrawal is correct. I have mixed views on that subject. I mean only to point out that these historic references are poor precedent in terms of predicting any result.