The Antarctic Treaty was signed in Washington on 1 December 1959 by the twelve countries whose scientists had been active in and around Antarctica during the International Geophysical Year (IGY) of 1957-58. It entered into force in 1961 and has since been acceded to by many other nations. The total number of Parties to the Treaty is now 53.
Some important provisions of the Treaty:
Antarctica shall be used for peaceful purposes only (Art. I)
Freedom of scientific investigation in Antarctica and cooperation toward that end … shall continue (Art. II).
Scientific observations and results from Antarctica shall be exchanged and made freely available (Art. III).
Among the signatories of the Treaty were seven countries - Argentina, Australia, Chile, France, New Zealand, Norway and the United Kingdom - with territorial claims , sometimes overlapping. Other countries do not recognize any claims. The US and Russia maintain a “basis of claim”. All positions are explicitly protected in Article IV, which preserves the status quo:
No acts or activities taking place while the present Treaty is in force shall constitute a basis for asserting , supporting or denying a claim to territorial sovereignty in Antarctica or create any rights of sovereignty in Antarctica. No new claim, or enlargement of an existing claim to territorial sovereignty in Antarctica shall be asserted while the present Treaty is in force.
To promote the objectives and ensure the observance of the provisions of the Treaty, "All areas of Antarctica, including all stations, installations and equipment within those areas … shall be open at all times to inspection " (Art. VII).