Our actual goal for the conflict is to keep the United States safe from terrorism. Afghanistan became the central front in that effort because, under Taliban rule, it was a safe haven for al-Qaeda to train recruits and plan attacks. But the means of achieving that goal -- building a stable, secure Afghan state -- has been confused with the ends. Too many are now viewing success or failure in Afghanistan in terms of whether a flourishing Afghan civil society will remain when we leave, and that goal is looking more and more unattainable in the short term, and maybe ever. Perhaps if we had invested the billions that went to the war in Iraq into infrastructure, schools and economic development in Afghanistan, we'd be in a stronger position now, but no signs have emerged from Afghanistan in recent years -- and particularly in the last few months -- to suggest that any kind of functional state is likely to emerge there, no matter how many troops we send.