Table 1

International Agreements that Limit Military Activities in Space

Agreements and their Principles/Constraints

United Nations Charter (1947)

Made applicable to space by the Outer Space Treaty of 1967.
Prohibits states from threatening to use, or actually using, force against the territorial integrity or political independence of another state (Article 2(4)).
Recognizes a state's inherent right to act in individual or collective self- defense when attacked. Customary international law recognizes a broader right to self-defense, one that does not require a state to wait until it is actually attacked before responding. This right to act preemptively is known as the right of anticipatory self-defense (Article 51).

Limited Test Ban Treaty (1963)

Bans nuclear weapons tests in the atmosphere, in outer space, and underwater.
States may not conduct nuclear weapon tests or other nuclear explosions (i.e., peaceful nuclear explosions) in outer space or assist or encourage others to conduct such tests or explosions (Article 1).

Outer Space Treaty (1967)

Outer space, including the Moon and other celestial bodies, is free for use by all states (Article I).
Outer space and celestial bodies are not subject to national appropriation by claim of sovereignty, use, occupation, or other means (Article II).
Space activities shall be conducted in accordance with international law, including the UN Charter (Article III).
The Moon and other celestial bodies are to be used exclusively for peaceful purposes (Article IV).
Nuclear weapons and other weapons of mass destruction (such as chemical and biological weapons) may not be placed in orbit, installed on celestial bodies, or stationed in space in any other manner (Article IV).
A state may not conduct military maneuvers; establish military bases, fortifications, or installations; or test any type of weapon on celestial bodies. Use of military personnel for scientific research or other peaceful purpose is permitted (Article IV).
States are responsible for governmental and private space activities, and must supervise and regulate private activities (Article IV).
States are internationally liable for damage to another state (and its citizens) caused by its space objects (including privately owned ones) (Article VII).
States retain jurisdiction and control over space objects while they are in space or on celestial bodies (Article VII).
States must conduct international consultations before proceeding with activities that would cause potentially harmful interference with activities of other parties (Article IX).
States must carry out their use and exploration of space in such a way as to avoid harmful contamination of outer space, the Moon, and other celestial bodies, as well as to avoid the introduction of extraterrestrial matter that could adversely affect the environment of the Earth (Article IX).
Stations, installations, equipment, and space vehicles on the Moon and other celestial bodies are open to inspection by other countries on a basis of reciprocity (Article XII).

Antiballistic Missile (ABM) Treaty (1972)

Between the US and USSR.
Prohibits development, testing, or deployment of space-based ABM systems or components (Article V).
Prohibits deployment of ABM systems or components except as authorized in the treaty (Article I).
Prohibits interference with the national technical means a party uses to verify compliance with the treaty (Article XII).

Liability Convention (1972)

A launching site is absolutely liable for damage by its space object to people or property on the Earth or in its atmosphere (Article II).
Liability for damage caused by a space object, to persons or property on board such a space object, is determined by fault (Article III).

Convention on Registration (1974)

Requires a party to maintain a registry of objects it launches into Earth orbit or beyond (Article II).
Information of each registered object must be furnished to the UN as soon as practical, including basic orbital parameters and general function of the object (Article IV).

Environmental Modification Convention (1980)

Prohibits military or other hostile use of environmental modification techniques as a means of destruction, damage, or injury to any other state if such use has widespread, long-lasting, or severe effects (Article 1).

Source: Adapted from Air Command and Staff College, Space Handbook (Maxwell AFB, Ala.: Air University Press, January 1985), 15-2 through 15-3.