The Northrop YF-23 Black Widow II is a multirole fighter and was designed for multirole missions: air superiority, close air support, and precision bombing. Its stealth technology makes it invisible to low-technology radar. The YF-23 was built by Northrop in the late 1980s as part of the Advanced Tactical Fighter (ATF) competition issued by the United States' government in 1986. The driving force behind the program was the American need for a next-generation aircraft intended to replace the F-15 Eagle to counter the Su-27 Flanker and MiG-29 Fulcrum of the Soviet Union after their discovery by Western satellites, which the US Air Force saw as nullifying the maneuverability advantage of existing US fighters. Today, the YF-23 Black Widow II is used by the Alliance of Nations under the name F-23 Black Widow, though the Axis of Empires used this aircraft as well, mainly the Consortium.