officially Pacific Security Treaty
Security pact for the South Pacific, signed in 1951 by Australia, New Zealand, and the U.S. (hence its acronym).
The U.S. first suggested a pact to Australia in the wake of the U.S.-Japan Security Treaty and fears of Japanese rearmament. The signatories agreed to maintain a consultative relationship for their collective security. In the 1980s New Zealand refused to let ships carrying nuclear weapons dock at its ports; the U.S., refusing to identify its nuclear-armed ships, suspended its treaty obligations to New Zealand in 1986, and the treaty has since been nonoperative with reference to New Zealand.