Secretary of Defense Robert Gates landed in Afghanistan today on an unannounced trip. Gates is meeting with Afghan President Hamid Karzai to begin assessments of how many U.S. troops can be withdrawn from the country in July. The war in Afghanistan has been going on for nearly a decade, making this one of the longest periods of sustained combat in U.S. history. Yet unlike past wars, only a small percentage of the population, namely military members and their families, carries the burden. A look at the costs of the wars in Afghanistan and Iraq and whether the military has a growing sense of isolation in its sacrifices.