If America can't win, how badly can we afford to lose?

In taking Marjah, an Afghan city, as an example, one can see that the peace established in Afghanistan under NATO control is fragile. Twelve months ago, Marjah was a bleak city squelched in the iron fist of the Taliban. Sharia law was ruthlessly enforced, and a sentiment of paralyzing fear permeated outside the core of power. There was little activity in the main square as the city was a ghost town (think post- Taliban portrayal of Kabul in "The Kite Runner" if you've seen the movie). However, as NATO forces have begun to reestablish security in Marjah, the schools are reopened and the Afghan national flag flies proudly in the main square. People have been able to crawl out from severe oppression to a life of (as the West would perceive it) normalcy. However, if the Obama administration attempts to withdraw troops by 2014, cities such as Marjah must be bolstered so that peace can perpetuate in the region. In fact, demonstrating the fragility of the current peace, one Marjah citizen portended that the Taliban would regain power in two weeks after NATO troops are withdrawn. It truly seems that NATO forces take two steps back for every one step forward. For example, while the troops were securing a tentative peace in Majah, other NATO soldiers further north were fired on and killed in roadside bombings. In fact, this past winter has been the most violent winter of the war, where the influx in troops is leading to that many more casualties. Moreover, as NATO troops are slated to withdraw in three years, the Afghan police will begin to face insurgency this spring, as the beginning of a transition of safeguarding from external to organic. To add salt to an open wound, General David Petraeus is expected to retire from his position as leader of the American initiative, evincing the military expert's wavering confidence in the success of the operation. Furthermore, governmental corruption has made Afghanistan "a personal fiefdom for a handful of war lords and kingmakers," claims an analyst of the Afghan situation. In fact, America's initiative to establish a stable government in Cairo has been hindered with the rampant corruption and Hamid Karzai's speculative faithful commitment in democracy. Moreover, statistics claiming a great improvement in Afghan life are mainly restricted to urban areas out of the Taliban's control where Americans are succeeding. Therefore, the core of the battle in establishing a democratic government in place of the Taliban is not too close to being achieved. Furthermore, Obama's setting a finite date to withdraw troops only encourages Al- Qaeda and the Taliban to hold down fort until that date, when they can prospectively take Afghanistan back to the bleak, radical Islamic republic that it was before the American troops arrived.
The situation is very bleak, and to avoid an even more taxing (economically and patriotically) war of attrition, NATO troops might have to pull out without forming Afghanistan as a shining beacon of democracy in the region. Moreover, the question begs to be asked: how much further before we can consider the job adequately completed? We can't pull out in three years and have the country launch back into chaos. The imposition of a finite withdrawal date is satisfying to Americans at home but is even more enticing to radical Islamic groups in Afghanistan. Who should Obama be more ruthless to?
Thanks,
Nikhil