By Douglas J. Gillert American Forces Press Service WASHINGTON -- To defend against the growing threat of missile attacks on foreign-based U.S. forces, DoD will accelerate development of a sea-based theater missile defense system. A perceived medium-range missile threat and past test failures of the Army ground-based Theater High Altitude Area Defense system provoked DoD into moving up the scheduled fielding of the Navy system from 2010 to 2007, according to Air Force Lt. Gen. Lester Lyles, Ballistic Missile Defense Organization director. DoD will continue funding the Army's THAAD system despite its repeated flight test failures. However, the Pentagon will pit it against the Navy Theater Wide system to determine which of the upper-tier defenses can be deployed first. "Tier" refers to a strategy of layered U.S. defenses. "Upper- tier" systems would intercept incoming long- and medium-range missiles during their flight in or above the outer atmosphere. "Lower-tier" systems defend at short to medium ranges against missiles in their late or final flight stages. "Because of the urgency in fielding an upper-tier system, we are going to continue flight-testing the THAAD interceptor missile and other elements of the system such as the radar," Defense Secretary William S. Cohen said at a Pentagon press conference Jan. 20. "Continued flight tests are going to provide data important for the upper-tier systems beyond the THAAD program." DoD will increase program funding of the Navy Theater Wide system by more than $500 million from fiscal 1999 to fiscal 2001, including funds added to the program by Congress last fall. The Pentagon will review both systems in late 2000 to assess costs, schedule, technical performance and risk, the secretary said. DoD then will determine the lead program. "Our goal is to have the lead system postured to deploy in the year 2007. Depending upon the results of the review, the other system might continue to be developed but at a much slower pace," Cohen said. The BMDO also will continue developing lower-tier defenses, including the Patriot Advanced Capability 3 and Navy Area missile systems. PAC-3 and Navy Area should be fielded by early fiscal 2001 and 2003, respectively, Lyles said. Both upper- and lower-tier systems work in conjunction with space-based sensors -- the same sensors that will be used for surveillance and early warning against missiles targeted at the United States, Lyles said. An airborne laser program, funded by the Air Force, adds to the array of defenses DoD wants to field. Battle management command, control and communications provides "the critical glue that holds all this together," Lyles said. "These lower-tier systems will provide effective defense capabilities against the shorter-range missile threats," Cohen said. "The threat to our forces is already extensive and growing, making it imperative that we field these important upgrades as soon as possible." The Pentagon also will reallocate $150 million originally slated for the Medium Extended Air Defense System, or MEADS. "We needed to focus initially on technologies that are relevant to the maneuver force protection that MEADS would have provided," Lyles said. That could be the PAC III or some other system already in the defense inventory, he said. The restructured MEADS money also could fund development of a mobile, 360-degree fire control radar and a mobile launcher, Lyles said. "We'll also make sure that we have the right kind of capability to address advanced threats like cruise missiles that the MEADS program was intended to address," Lyles said. "We need to have lower-tier systems, we need to have upper-tier systems, and we need to have multiplatforms on the land, from the sea and also from air," Lyles said. "We need to make sure that all of these systems work together and can be interoperable. That's formed the heart of our program for theater missile defense. "What has changed over the last year, however, is the growing urgency of making sure that we have an upper-tier capability to counter the growing medium-range threat," he said. Lyles said this threat comes from offensive missiles like the North Korean No Dong, Iranian Shihab III and Pakistani Ghari. "We need to make sure that we have the capability to negate those threats."