In this Saturday, Jan. 28, 2012 file photo, U.S. soldiers, part of the NATO- led International Security Assistance Force (ISAF) walks, as a U.S. Chinook helicopter is seen on the back ground near the place where the foundation of a hospital was laid in Shindand, Herat, west of Kabul, Afghanistan. The phrases to describe some of the looming foreign policy challenges for U.S. President Barack Obama didn't even exist when he took the oath of office the first time: the Arab Spring, the Fordo Facility housing Iran's underground uranium enrichment labs, the stealth power of new viruses bearing names such as Stuxnet and Flame in the shadow world of cyber-sabotage. While the war in Afghanistan, now in its 12th year, was barely a topic on the campaign trail, the country will certainly command a great deal of Obama's attention in his second term. Obama soon will receive his top military officials' recommendations about how fast to withdraw the roughly 66,000 U.S. troops still in Afghanistan. The first 33,000 American troops withdrew by the end of September.