Twelve nations, including the United States and the Soviet Union, sign the , which bans military activity and weapons testing on that continent. It was the first arms control agreement signed in the Cold War period.
Since the 1800s a number of nations, including Great Britain, Australia, Chile and Norway, laid claim to parts of Antarctica. These competing claims led to diplomatic disputes and even armed clashes. In 1948, Argentine military forces fired on British troops in an area claimed by both nations. Incidents of that sort, together with evidence that the Soviet Union was becoming more interested in Antarctica, spurred the United States to propose that the continent be made a trustee of the United Nations. This idea was rejected when none of the other nations with interests on the continent would agree to cede their claims of sovereignty to an international organization.
By the 1950s, some officials in the United States began to press for a more active U.S. role in Antarctica, believing that the continent might have military potential as an area for nuclear tests. President Dwight D. Eisenhower, however, took a different approach. U.S. diplomats, working with their Soviet counterparts, hammered out a treaty that set aside Antarctica as a military-free zone and postponed settling territorial claims for future debate. There could be no military presence on the continent, and no testing of weapons of any sort, including nuclear weapons. Scientific ventures were allowed, and scientists would not be prohibited from traveling through any of the areas claimed by various nations. A dozen nations signed the document. Since the treaty did not directly tamper with issues of territorial sovereignty in Antarctica, the signers included all nations with territorial claims on the continent. As such, the treaty marked a small but significant first step toward U.S.-Soviet arms control and political cooperation. The treaty went into effect in June 1961, and set the standard for the basic policies that continue to govern Antarctica.