Instead, we brought NATO in, put tens of thousands of troops in and declared our determination to build an Afghan democracy that would be a model for the Islamic world, where women's rights were protected.
After inviting the world to observe how the superpower succeeds in taking down a tyranny and creating a democracy, we will have failed, and we will be perceived by the whole world to have failed.
While there was no vital U.S. interest in Afghanistan before we went in, we have invested so much blood, money and prestige that withdrawal now -- which would entail a Taliban takeover of Kabul and the Pashtun south and east -- would be a strategic debacle unprecedented since the fall of Saigon.
But what if Obama approves McChrystal's request and puts another 20,000 to 40,000 U.S. troops into the war?
Certainly, that would stave off any defeat. But what is the assurance it would bring enduring victory closer? The Taliban have matched us escalation for escalation and are now militarily stronger than at any time since the Northern Alliance, with U.S. air support, ran them out of Kabul.
About the political consequences of escalation, there is no doubt.
Obama would divide his party and country. His support would steadily sink as the roll call of U.S. dead and wounded inexorably rose. He would watch as the NATO allies moved toward the exit and America was left alone to fight alongside the Afghans in a seemingly endless war.
Consider. If there were no Americans in Afghanistan today, and the Taliban were on the verge of victory, how many of us would demand the dispatch of 68,000 troops to fight to prevent it? Few, if any, one imagines.
What that answer suggests is that the principal reason for fighting on is not that Afghanistan is vital, but that we cannot accept the American defeat and humiliation that withdrawal would mean.
Thus Obama's dilemma: Accept a longer, bloodier war with little hope of ultimate victory, a decision that could cost him his presidency. Or order a U.S. withdrawal and accept defeat, a decision that could cost him his presidency.
In such situations, presidents often decide not to decide.
Harry Truman could not decide in Korea. LBJ could not decide in Vietnam. Both lost their presidencies. Ike and Nixon came in, cut U.S. losses and got out. The country rewarded both with second terms.