The original Signatories to the Treaty are the twelve countries that were active in Antarctica during the International Geophysical Year of 1957-58 and then accepted the invitation of the Government of the United States of America to participate in the diplomatic conference at which the Treaty was negotiated in Washington in 1959. These Parties have the right to participate in the meetings provided for in Article IX of the Treaty (Antarctic Treaty Consultative Meetings, ATCM).
Since 1959, 44 other countries have acceded to the Treaty. According to Art. IX.2, they are entitled to participate in the Consultative Meetings during such times as they demonstrate their interest in Antarctica by “conducting substantial research activity there” . Seventeen of the acceding countries have had their activities in Antarctica recognized according to this provision, and consequently there are now twenty-nine Consultative Parties in all. The other 27 Non-Consultative Parties are invited to attend the Consultative Meetings but do not participate in the decision-making.
