The U.S. has remained in Afghanistan this long on the assumption that it was a war we had to win: Pull out and we would soon be back where we were on Sept. 10, 2001, with the Taliban in control and al-Qaida enjoying a refuge from which to launch attacks. But our safety does not require us to stay there to engage in the costly and open-ended projects known as nation-building, or even to defeat the extremists.Before the attacks on New York and Washington, the U.S. government was averse to going after our enemies in Afghanistan. But no jihadist in the most remote reaches of Helmand province could possibly expect a repetition of that forbearance. Even if the Taliban were to regain power, they and al-Qaida would know that any attempt to strike American targets would assure another cataclysmic response.
Today's "safe haven" for terrorists actually lies in Pakistan, which the U.S. has not seen the need to invade. The threat to Pakistan from Islamic extremists is commonly offered as another rationale for our presence in Afghanistan. But as the war has continued, Pakistan has grown less stable and more vulnerable, suggesting that our efforts are either ineffectual or counterproductive.
The same could be said of our entire mission. The Soviets went into Afghanistan in 1979 in the mistaken belief that the invasion would enhance their security. Nine years later, they admitted failure and went home. Staying longer than they did doesn't mean we will be more successful.