By Douglas J. Gillert American Forces Press Service WASHINGTON -- With deployed U.S. forces increasingly threatened by medium-range missile attacks, Defense Secretary William S. Cohen announced Jan. 20 that DoD will step up development of an expanded theater missile defense capability. While DoD will continue to fund the Army's Theater High Altitude Area Defense system, Cohen said, the Navy Theater Wide system could become the lead program. He said DoD will increase funding for the Navy system by more than a half-billion dollars through fiscal 2001. Meanwhile, the Pentagon will review both systems in 2000, with the goal of fielding one of them as early as 2007. The Navy Theater Wide and Army THAAD systems are designed to counter threats above the atmosphere from the sea and ground, respectively. The Ballistic Missile Defense Organization, DoD's missile defense agency, also will continue developing lower-tier systems, including the Patriot Advanced Capability-3 missile and the Navy Area Ballistic Missile Defense System. Each of these defensive systems is briefly described below. For more information about DoD missile defense programs, visit the BMDO Web site at www.acq.osd.mil/bmdo. More information on the Air Force's airborne laser program is available at the Air Force Research Laboratory Web site at www.de.afrl.af.mil/abl/index.html. DoD Theater Missile Defense Systems Navy Theater Wide System: Upper-tier (above the atmosphere) ballistic missile defense capability from Aegis missile-equipped surface combatant ships. Mission: Provide intercept capability against medium- and long- range theater ballistic missiles. Advantages: Capitalizes on inherent mobility of Navy ships. By positioning a ship closer to the threat launch point, a significant increase in the defended area can be realized. Placement near enemy launch sites provides ability to intercept targets at various descent phases, offer additional layer of defense for lower-tier systems. Theater High Altitude Area Defense System: Land-based, upper-tier defensive missile system with long-range and high-altitude intercept capability. Consists of four principal elements: truck-mounted launchers, interceptors, radar system, and battle management command, control, communications and intelligence system. Mission: Defeat tactical theater ballistic missiles; intercept missiles inside and outside the atmosphere; engage at long ranges and high altitudes; give U.S. and allied forces multiple opportunities to intercept incoming missiles. Advantages: Ability to intercept missiles at long range and high altitude would give U.S. forces best chance to shoot down incoming missiles far enough out to avoid harm from post- intercept debris. Battle management command and control system would link with other missile and air defense systems. All components can be airlifted. Patriot Advanced Capability System: Designed to provide the lower tier of ballistic missile defense architecture. Consists of four basic components: radar set, engagement control station, launching station and interceptors. Mission: Defend troops and fixed assets against short- and medium-range ballistic missiles, cruise missiles and other air- breathing threats, such as fixed- and rotary-wing aircraft. Designed for hit-to-kill accuracy in the terminal phase of the threat missile's flight. Advantages: High maneuverability and hit-to-kill accuracy; interoperable with other Army and joint systems; air- transportable to support rapid deployments. Airborne Laser System: Modified Boeing 747-400F aircraft with multiple laser modules to create a megawatt-class chemical laser. Mission: Shoot down theater ballistic missiles shortly after they're launched. Protect civilian and key military assets from attack by missiles such as the Scuds used by Iraq during the Persian Gulf War. Advantages: Provides means to destroy theater ballistic missiles when they are most vulnerable -- in their boost phase; will become deterrent against weapons of mass destruction by confronting adversary with the prospect those weapons will fall back on its own territory. Will provide aerial dominance combined with other airborne weapon systems -- specifically, the F-22 and Joint Strike Fighter. Navy Area System: Aegis cruisers and destroyers equipped with a modified Aegis combat system. Mission: Defend U.S. and allied forces and areas of vital national interest against theater ballistic missiles. Detect and track short- to medium-range theater ballistic missiles and engage them with the SM-2 interceptor. Advantages: Protect U.S. forces deployed to crisis areas; provide early engagement and defense in depth to reassure allies; Enable reinforcements by protecting debarkation ports, airfields and staging areas; ease strain required for timely airlift and sealift; deter conflict.