Over recent decades, Australia's foreign relations have been driven by a close association with the United States through the ANZUS pact, and by a desire to develop relationships with Asia and the Pacific, particularly through Association of Southeast Asian Nations (ASEAN), the Pacific Islands Forum and the Pacific Community, of which Australia is a founding member. In 2005, Australia secured an inaugural seat at the East Asia Summit following its accession to the Treaty of Amity and Cooperation in Southeast Asia, and in 2011 attended the Sixth East Asia Summit in Indonesia. Australia is a member of the Commonwealth of Nations, in which the Commonwealth Heads of Government meetings provide the main forum for co-operation. Australia has pursued the cause of international trade liberalisation. It led the formation of the Cairns Group and Asia-Pacific Economic Cooperation.