The continent of Antarctica (see Figure 8.1) belongs to no nation, although a number of states have made claims on sections of it. This unusual state of affairs was created by the 1959 Antarctic Treaty, which came into full force in 1961 and is often referred to as the Antarctic Treaty System (ATS). Australia, Argentina, Belgium, Japan, Norway, South Africa, France, Chile, Great Britain, the Soviet Union, New Zealand, and the United States negotiated the original treaty, and since then forty-one nations have signed it, thereby showing approval of the treaty's aims and committing themselves to its execution. For the first thirty years of the agreement, the treaty could only be revised through unanimous agreement of the voting members. After thirty years, any voting member could call a conference to review the treaty.