Almost 150,000 U.S. and allied troops are now in Afghanistan, some 30,000 more than the number of Soviet troops at the height of their occupation in the 1980s. The U.S.-led International Security Assistance Force (ISAF) is now at the pinnacle of its strength, which is expected to start declining, one way or another, by the latter half of 2011, a trend that will have little prospect of reversing itself. Though history will undoubtedly speak of missed or squandered opportunities in the early years of the U.S. war in Afghanistan, this is now the decisive moment in the campaign.