You don't. I want to spin a quick yarn about a country back in the 1970s and 1980s that played a massive role in bringing down one of the most militarized nation-states in recent history. This country was a mountainous region with a very weak central government and was ruled over mostly by tribal warlords and religious extremists. When a very large nation-state to the north encroached on their territory and wanted to export their version of government, the tribal warlords and religious extremists mobilized against this foreign force. They eventually wore down the foreign army over nearly a decade, forcing them to withdraw. Now, we all know that the foreign army that retreated was the Soviet Union and the mountainous country it failed to keep under its control was Afghanistan. And clearly the story is a little more complex than a short paragraph (CIA Stingers, ISS corruption, etc.). But the fundamentals remain the same: the Afghan mujahideen was able to draw the Soviets into Afghanistan and then embarrass them on the world stage during the Soviet-Afghan War.
Fast forward to 2001 and while some of the circumstances have changed, the fundamentals remain the same. We've been drawn into Afghanistan by a Soviet-Afghan War veteran who understands how powerful guerrilla warfare tactics can be against a superior military. Compounding this, bin Laden has had two very lucky breaks. The first was Tora Bora in November, 2001 when we let him get away (a conclusion reached five months after the fact but made "official" by the Senate this week) and the second was Iraq. If we catch bin Laden in November we take out a major figurehead of the terrorist movement in Afghanistan and clearly and unequivocally send the message that you do not fuck with the United States. Instead bin Laden escapes because of crucial errors in judgment and tactics, becoming an even more mythic figure. Secondly, we go into Iraq, allowing Afghanistan to be relegated to red-headed stepchild status, with funds, troops, and materials diverted to the desert to find non-existent WMDs.
At the height of the Soviet-Afghan War, the Soviets had about 118,000 troops fighting in Afghanistan. With Obama's plan to send another 30,000 troops to the war-torn country it will bring American troop levels to about 100,000 (with an additional 45,000 NATO troops). We are, essentially, sticking to the game plan that the Soviets had back in the 80s, at least in terms of troop levels. If it did not work for them, what could possibly make those in Washington think it will work for us?
We could sit here all day and talk about the failures of the past 8 years in Afghanistan, but that's not going to help with the future. What are our options there? I don't know, as I don't have top-level security clearance. Going on public information, though, one major issue is the Federally Administered Tribal Areas in Pakistan that border Afghanistan, where it is believed bin Laden is hiding out and from where Al-Qaeda is launching attacks on American forces. We could talk to Pakistan to try to get permission to follow skirmishing Al-Qaeda/Taliban/Haqqani forces whose tactics include ambushing our armed forces and running back over the Zero Line, but Islamabad has no tangible control over the area. We could try to set up something similar to a DMZ on the border of Pakistan and Afghanistan akin to that between North and South Korea and try to contain the terrorist forces. We could pack up and leave like we did in the 80s and allow the area to fall out of control (yet again) and hope we don't get attacked twenty years down the road. Pick your poison.
It's important to remember that in war nobody wins. Whether the insurgent forces in Afghanistan/Pakistan want to claim victory or the Americans and their "coalition of the willing" want to claim victory, the reality is we have all lost. Afghanistan has become even more war-torn, is now home to 90% of smack production in the world, and is stuck between two warring groups. Americans have seen our reputation both at home and abroad mocked, we've lost nearly 1,000 men and women in Afghanistan alone (with that number rising each year), and we will more than likely have some type of military presence in the country for at least a decade. You want the definition of a quagmire, here it is.