Strategic Defense Initiative in the context of "Missile defense"

The United States Space Force (USSF) is the space service branch of the United States Armed Forces, and was established on 20 December 2019. Part of the United States Department of Defense, it is one of the six armed forces of the United States and one of the eight uniformed services of the United States. It is the second independent space force to have been formed, after the Russian Space Forces; together with that of China, it is one of only two still extant.

The United States Space Force traces its origins to the Air Force, Army, and Navy's military space programs created during the beginning of the Cold War. US military space forces first participated in combat operations during the Vietnam War and have participated in every U.S. military operation since, most notably in the Gulf War, which has been referred to as the "first space war". The Strategic Defense Initiative and creation of Air Force Space Command in the 1980s marked a renaissance for military space operations.

The 863 program (Chinese: 863计划) or State High-Tech Development Plan (Chinese: 国家高技术研究发展计划) was a program funded and administered by the government of the People's Republic of China intended to stimulate the development of advanced technologies in a wide range of fields for the purpose of rendering China independent of financial obligations for foreign technologies. It was inspired by the Strategic Defense Initiative proposed by U.S. president Ronald Reagan in 1983, and was absorbed alongside Program 973 into the "National Key R&D Program" in 2016.

On March 3, 1986, the program was suggested by Wang Daheng, Wang Ganchang, Yang Jiachi, and Chen Fangyun in a letter to China's paramount leader Deng Xiaoping, who approved the program within 2 days. The program was initially led by Zhao Ziyang, who was the premier of China at the time, and received a governmental fund of 10 billion RMB in 1986, which accounts for 5% of the total government spending that year. According to the US National Counterintelligence and Security Center, the 863 program "provides funding and guidance for efforts to clandestinely acquire US technology and sensitive economic information."

A kinetic energy weapon (also known as kinetic weapon, kinetic energy warhead, kinetic warhead, kinetic projectile, kinetic kill vehicle) is a projectile weapon based solely on a projectile's kinetic energy to inflict damage to a target, instead of using any explosive, incendiary, chemical or radiological payload. All kinetic weapons work by attaining a high flight speed – generally supersonic or even up to hypervelocity – and collide with their targets, converting their kinetic energy and relative impulse into destructive shock waves, heat and cavitation. In kinetic weapons with unpowered flight, the muzzle velocity or launch velocity often determines the effective range and potential damage of the kinetic projectile.

Kinetic weapons are the oldest and most common ranged weapons used in human history, with the projectiles varying from blunt projectiles such as rocks and round shots, pointed missiles such as arrows, bolts, darts, and javelins, to modern tapered high-velocity impactors such as bullets, flechettes, and penetrators. Typical kinetic weapons accelerate their projectiles mechanically (by muscle power, mechanical advantage devices, elastic energy or pneumatics) or chemically (by propellant combustion, as with firearms), but newer technologies are enabling the development of potential weapons using electromagnetically launched projectiles, such as railguns, coilguns and mass drivers. There are also concept weapons that are accelerated by gravity, as in the case of kinetic bombardment weapons designed for space warfare.

Leslie Aspin Jr. (July 21, 1938 – May 21, 1995) was an American Democratic Party politician and economist who served as the U.S. representative for Wisconsin's 1st congressional district from 1971 to 1993 and as the 18th United States Secretary of Defense under President Bill Clinton from 1993 to 1994.

In Congress, Aspin had a reputation as an intellectual who took a middle-of-the-road position on controversial issues. He supported the Reagan administration regarding the MX missile and aid to the Nicaraguan Contras, but he opposed the B-2 bomber and the Strategic Defense Initiative. He played a major role in convincing the House to support the January 1991 resolution supporting the use of force by President George H. W. Bush against Iraq, after it invaded Kuwait.