The Antarctic Treaty and related agreements, collectively called the Antarctic Treaty System or ATS, regulate international relations with respect to Antarctica, Earth's only continent without a native human population. For the purposes of the treaty system, Antarctica is defined as all land and ice shelves south of 60°S latitude. The treaty has now been signed by 47 countries, and set aside Antarctica as a scientific preserve, established freedom of scientific investigation and banned military activity on that continent. This was the first arms control agreement established during the Cold War.