Increasing attention is being focused on current Department of Defense (DoD) plans for an integrated, joint cruise missile defense (CMD) capability to protect the United States. The threat posed by the shorter-range, relatively inexpensive cruise missile has long been considered primarily a theater/geographic combatant commander issue. The services have devoted considerable resources to addressing this theater mission area based on their respective service needs. However, with the advent of more easily attainable missile guidance and weapons technology, a wide variety of potential adversaries can now buy or build a cruise missile to directly attack the United States. The missiles’ proven effectiveness and the ease of obtaining cruise missiles are especially attractive to terrorists or other non-state actors, making proliferation even more disconcerting. Given these trends, the threat of an attack by a cruise missile on the United States is ever more plausible and the necessity for a coherent defense against this threat is increasingly urgent. The challenge will be to integrate all the service-focused capabilities into a joint integrated warfighting architecture that develops synergy and efficiency from weapon system engineering, risk mitigation and cost effective development processes. Current efforts to create this focus include designating a single integrating authority with a lead agency or organization with the authority to facilitate joint, interagency and multinational CMD integration.DoD defines a cruise missile as “a guided missile, the major portion of whose flight path to its target is conducted at approximate constant velocity; depends on the dynamic reaction of air for lift and upon propulsion forces to balance drag.” Cruise missiles can be launched from the air, from ships and submarines at sea or from land. While cruise missiles are not new weapons, the technology now available is making them much more accurate, versatile and lethal.Cruise missiles are an especially difficult target for current active defenses to detect, track and intercept. Defenses that exist today protect only small areas or unique, highvalue assets. The best defense against a cruise missile would be—as for protecting against ballistic missile attack—to destroy the launch platform prior to launch. However, because of the relatively small size and modest launching infrastructure needed to support a cruise missile, finding and neutralizing it with offensive, preemptive counterforces may be problematic for any joint force commander.Deployed forces of the United States and its allies have typically been regarded as the primary targets of a cruise missile threat. In Operation Iraqi Freedom, U.S. forces were targeted by Land Attack Cruise Missiles (LACMs) for the first time. However, the fact that LACMs historically have been used in overseas areas does not preclude their use against the U.S. homeland. While current cruise missile inventories have mostly modest ranges, it is very feasible to launch cruise missiles using asymmetrical tactics and 2 locations. For example, some 75 percent of the population of the United States and 80 percent of its economic power are located within 200 miles of a coastline. With increasing threats of cruise missiles armed with Weapon of Mass Destruction (WMD) warheads, there is a real possibility of significant damage to key population centers and vital, homeland-based military assets.DoD recognizes the pressing need for an improved active defensive capability to protect the homeland from attack by cruise missiles. At the same time, any improvements in homeland defense capabilities will also improve CMD of deployed forces, friends and allies. While some CMD capability already exists and technology for improvement is being developed by the services, the processes necessary to integrate into a holistic, warfighter operational and system architecture are lagging.