By the time I started working at the Defense Department in the early years of the Obama administration, the Pentagon's 17.5 miles of corridors had sprouted dozens of shops and restaurants catering to the building's 23,000 employees. And, over time, the U.S. military has itself come to offer a similar one-stop shopping experience to the nation's top policymakers. As retired Army Lt. Gen. Dave Barno once put it to me, the relentlessly expanding U.S. military has become a Super Walmart with everything under one roof" - and two successive presidential administrations have been eager consumers. The military's transformation into the world's biggest one-stop shopping outfit is ... at once the product and the driver of seismic changes in how we think about war, with consequent challenges both to our laws and to the military itself. We've gotten into the habit of viewing every new threat through the lens of "war," thus asking our military to take on an ever-expanding range of nontraditional tasks. But viewing more and more threats as "war" brings more and more spheres of human activity into the ambit of the law of war, with its greater tolerance of secrecy, violence, and coercion - and its reduced protections for basic rights. Meanwhile, asking the military to take on more and more new tasks requires higher military budgets, forcing us to look for savings elsewhere. As budget cuts cripple civilian agencies, their capabilities dwindle, and we look to the military to pick up the slack, further expanding its role.