On November 6 Americans will vote for their next commander-in-chief, the first of the duties assigned to the president by the constitution. The security outlook he will face is in flux. There are plans for a “rebalancing” of military attention to the Asia Pacific region, new tensions over old islands in the western Pacific, and even speculation over a novel “Air-Sea” operational concept, which would integrate air force and navy capabilities to deter – and, if need be, to counter – precision missiles and other weapons that could threaten America’s projection of power across oceans.