The 1967 Outer Space Treaty, also known as the “Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and other Celestial Bodies,” is a multilateral agreement initiated by the United States, the United Kingdom and the Soviet Union. Its primary objective was the implementation of international law governing space exploration, weapons testing and territorial claims. It was drafted and signed in 1967 by more than 100 countries and has since been ratified by 95 countries. The original provisions of the treaty are still in effect today.
Article VI contains the bulk of the treaty’s arms control requirements. Among the key principles enshrined is that space is to be used for peaceful purposes only. This means that countries cannot:
- Place nuclear weapons or other weapons of mass destruction in Earth’s orbit, on the moon, or on any celestial body.
- Use the moon or any celestial body to test weaponry of any kind, including nuclear weapons.
The treaty was born from the emergence of intercontinental ballistic missiles (ICBMs) and other long-range rocket systems, during a period commonly referred to as “The Space Race.” Both the West and the Soviet Union shared the opinion that space should be neutral territory and off limits for weapons and weapons testing; however, peripheral disagreements regarding U.S. foreign basing prevented the two from reaching a formal settlement.
Finally, the Limited Test Ban Treaty of 1963 included key provisions banning the testing of nuclear weapons in the atmosphere, underwater and in space, which assuaged Soviet concerns and allowed them to agree to the broader provisions in the Outer Space Treaty.
The General Assembly of the United Nations provided the multilateral forum by which a formal resolution banning weapons activity in space could be adopted. By 1966, both the United States and the Soviet Union submitted draft treaties and began negotiations. The agreement was signed in January 1967 and was formally ratified by the U.S. Senate in October the same year.