At the core of the ANZUS alliance is a commitment by Australia and the United States to consult each other in the event of a threat or armed attack on either party, and to ‘act to meet the common danger in accordance with … constitutional processes’.

Donald Trump has brought new urgency to the debate about whether the United States would come to Australia’s defence should Australia be attacked. Trump’s antipathy towards alliances, and his remarks that he would not defend European allies that do not spend enough on defence (in apparent rejection of NATO’s collective defence obligation), have cast doubt on whether he might also step back from mutual defence commitments with other allies.

However, a clear majority of Australians (63%) continue to think that the United States would come to Australia’s defence if it were attacked. Only one-third (33%) think the United States would not defend Australia.

In previous years, in response to a similar question, a significantly higher proportion of Australians (about three-quarters in 2019, 2021, and 2022) agreed with the statement ‘the United States would come to Australia’s defence if Australia was under threat’.

United States’ defence of Australia