The Canberra Pact was a treaty of mutual defence between the governments of Australia and New Zealand, signed on 21 January 1944. This Pact was not a military alliance; its focus was on working together on issues of mutual interest. New Zealand and Australia signed the pact in order to promote national interests in the postwar negotiations. They wanted a vital stake in the disposition of the islands south of the equator and knew that they needed to do this to have their voice heard by the other allies.
In the wake of Japan's expansion into the Pacific region during the Second World War, New Zealand and Australia looked at working more closely together. The Canberra Pact represented an undertaking by both countries to co-operate on international matters, especially in the Pacific. In particular they agreed to:
- consult on matters of common interest
- oppose the placement of military installations in the region
- support the principle of trusteeship for the remaining Pacific island colonies, and
- set up a Regional Commission with the purpose of advancing the economic, political and social development of the region.
The Canberra Pact was the first treaty signed independently by New Zealand.
The United States opposed the Canberra Pact as it was made without their consultation, and the pact clearly outlined strategic boundaries in the Pacific, which the United States regarded as imposing on their sphere of interest. The prime ministers of New Zealand and Australia were subjected to a very demeaning dressing-down by Secretary of State Hull as a sign of American displeasure. In addition, New Zealand's armed forces in the Pacific theatre of operations were effectively sidelined as a result.