to carry electronic jamming units, its sole purpose being to fly into enemy airspace and confuse enemy radar so that the strike package could follow and accomplish the mission, replacing the venerable Douglas RB/EB-66 of the 1950s and 1960s that served in the Vietnam War. A new version of the F-15, the F-15E Strike Eagle, was also developed to replace the F-111E/F tactical strike aircraft in TAC's and USAFE's arsenal. Developed from the twin-seat F-15B, the Strike Eagle was designed for long-range interdiction of enemy ground targets deep behind enemy lines while concurrently retaining air-to-air combat capability. The first F-15Es were deployed to the 4th Tactical Fighter Wing at Seymour Johnson AFB, North Carolina on 29 December 1988. Across the Nevada desert skies in the 1980s, there were reports of strange lights in the night skies, with some of these reports explained as possible UFOs. Most of these reports seem to come from the area around Tonopah and another area identified on maps as Nellis AFB's Area 51. The UFO story seemed to hold water, as the USAF radars at Nellis and FAA radars at Las Vegas could not see any aircraft in the area of question. The strange lights over the Nevada desert were officially recognized in November 1988 when the Department of Defense unveiled the F-117 Nighthawk stealth aircraft, an outgrowth of USAF's Have Blue reduced radar cross-section (RCS) research aircraft. Although ostensibly designated as a "fighter," the F-117 was actually a precision light bomber with no air-to-air combat capability. The F-117 was a well-kept secret throughout the 1980s. The first prototype aircraft had first flown in 1981 and one had crashed in June 1984 in the Nevada desert. It took another crash of the aircraft in California in 1988 to finally lift the veil of secrecy. On 9 May 1992, four Lockheed F-117A Nighthawks from the Tonopah Test Range Airport, Nevada, arrived at Holloman AFB, New Mexico and were assigned to the 49th Tactical Fighter Wing. Collapse of the Warsaw Pact One of the effects of this massive buildup of American military might during the 1980s was pressure inside of the Soviet Union to match the United States. However, internal pressures inside the Soviet Union for increased freedoms, along with economic pressures led to the loosening of their control in Eastern Europe. In 1989, one by one of these nations in Eastern Europe began to rebel against