Mark Gunzinger: Upgrading nation's aging nuclear arsenal
Summary: Military planners are hard at work on what they say are badly needed upgrades to the nation's aging nuclear arsenal. A new bomber, new submarines and new intercontinental ballistic missiles - all under development contracts. Still undecided is whether the U.S. will develop a new air-launched cruise missile. For more on that program, we turn to Mark Gunzinger, analyst at the Center for Strategic and Budgetary Assessments.