opened its ports to the Royal New Zealand Navy once again, and under the presidency of Bill Clinton in the US and the government of Helen Clark in New Zealand, the countries have since reestablished bilateral cooperation on defence and security for world peace. While ANZUS is commonly recognised to have split in 1984, the Australia–US alliance remains in full force. Heads of defence of one or both states often have joined the annual ministerial meetings, which are supplemented by consultations between the US Combatant Commander Pacific and the Australian Chief of Defence Force. There are also regular civilian and military consultations between the two governments at lower levels. Annual meetings to discuss ANZUS defence matters take place between the United States Secretaries of Defense and State and the Australian Ministers of Defence and Foreign Affairs are known by the acronym AUSMIN. The AUSMIN meeting for 2011 took place in San Francisco in September. The 2012 AUSMIN meeting was in Perth, Western Australia in November. Unlike the North Atlantic Treaty Organization (NATO), ANZUS has no integrated defence structure or dedicated forces. Nevertheless, Australia and the United States conduct a variety of joint activities. These include military exercises ranging from naval and landing exercises at the task-group level to battalion-level special forces training, assigning officers to each other's armed services, and standardising equipment and operational doctrine. The two countries also operate several joint-defence facilities in Australia, mainly ground stations for spy satellite, and signals intelligence espionage in Southeast and East Asia as part of the ECHELON network. During the 2010s, New Zealand and the US resumed a close relationship, although it is unclear whether the revived partnership falls under the aegis of the 1951 trilateral treaty. The Wellington Declaration of 2010 defined a "strategic partnership" between New Zealand and the US, and New Zealand joined the biennial Rim of the Pacific military exercise off Hawaii in 2012, for the first time since 1984. The US prohibition on New Zealand ships making port at US bases was lifted after the 2012 exercise. History Origins In the years following the Second World War, Australia and New Zealand began pressing the United States for a formal security guarantee. The two governments felt threatened by the possibility of a resurgent Japan and the spread of communism to their North. Additionally, the fall of Singapore in 1942 had demonstrated that their traditional protector, the United Kingdom,