What is the ANZUS Treaty?

It’s an agreement between Australia, New Zealand and the U.S. (hence the name ‘ANZUS’), signed on September 1, 1951, requiring each nation to “consult together whenever in the opinion of any of them the territorial integrity, political independence or security of any of the Parties is threatened in the Pacific”. The three nations pledged to 'act to meet the common danger'.

Although, in 1986, New Zealand become a nuclear-free zone, meaning nuclear-capable U.S. warships were refused entry. This led to the U.S. ridding itself of any obligations towards New Zealand, with a partial suspension. However, in 2012, New Zealand lifted a ban on visits by U.S. warships.

It’s important to note that the agreement does not require any of the nations to provide military support to each other. This topic in particular sometimes causes tension for Australia, with some expressing disappointment for the minimal support received from the U.S. during the Konfrontasi conflict in Indonesia and Malaysia in the early 1960s.

Has the treaty ever been invoked?

Once, in 2001 after the 9/11 terrorist attacks, Australian Prime Minister at the time John Howard formally invoked the ANZUS treaty as a response to the attacks, leading to Australia’s involvement in the U.S. led ‘War on Terror’. While not being technically invoked, commitments have been linked to the ANZUS treaty, including Australia’s commitment to the Vietnam War.

Contemporary relevance

The basic foundations of the treaty remain, acting as an alliance between the nations. The treaty is responsible for current security-related activities between the U.S. and Australia. Despite New Zealand allowing the U.S. warship visits from 2012, the U.S. and New Zealand no longer maintain the security relationship between their countries.

Chief of the Defence Force General, Angus Campbell, said on the relations, “today I reflect on the long history of mateship between Australia and the United States, and remember those who laid down their lives to protect the security and prosperity of our two nations”.

Further commenting on the current relations, Australian Secretary of Defence Greg Moriarty said, “the alliance continues to evolve to meet our shared security challenges”.