CANBERRA, Australia — When Australia’s prime minister, Scott Morrison, proclaimed a new “forever partnership” strengthening military ties with the United States, it was a decisive step in his country’s trailblazing push against a more assertive China.
The decision this month to acquire American nuclear-powered submarines showed that even as Beijing has pummeled Australia with sanctions and a freeze on high-level talks, Australian officials are determined to maintain a sharp turn in policy and tone toward China, despite a descent in relations to their deepest chill in decades.
“This was Australia acting in our national interests to ensure our national security in our region,” Mr. Morrison told reporters while visiting the United States last week. “That is our job, to keep Australians safe.”
Behind the resolute face on the international stage, though, there are murmurs of disquiet at home. Four years into its confrontation with China,…