Australia’s refusal to support a US-led military offensive against Iran has raised questions over the future of their security alliance as US President Donald Trump’s policies threaten to drive a wedge between the two longstanding allies.

Canberra is sending a frigate and surveillance plane to a US task force protecting freedom of navigation through the Strait of Hormuz. But Prime Minister Scott Morrison said Friday in Washington it won’t be drawn into a war with Iran, or help the US ratchet up pressure against China in its trade war.

“The other matters that are being pursued by the United States are matters that they’re pursuing, and I made it very clear when we announced our involvement that it was very much about that freedom of navigation issue and that’s what it is about and that’s appreciated,” Morrison said at a lavish White House dinner in his honor hosted by Trump.

Trump floated the idea of a military strike against Iran at a press briefing with Morrison, even suggesting that he might use nuclear weapons. The US could knock out 15 significant targets in Iran, the US leader warned. “I could do it right here,” he said. “It’s all set to go. I could do it right here and then you’d have a nice big story to report.”

He had lots to say about China, too, which “is a threat to the world in a sense, because they’re building a military faster than anybody, and … they’re using US money.”

While Trump later backtracked on the threat to nuke Iran, he is expected to lobby other world leaders to back his Hormuz military alliance in talks at the United Nations this week. Trump has already sent more US troops and missile systems to Saudi Arabia and the United Arab Emirates in response to a drone attack on Saudi oil facilities that his administration has blamed on Iran.

US President Donald Trump and First Lady Melania Trump welcome Australian Prime Minister Scott Morrison and Jennifer Morrison at the White House. Photo: Pool via CNP/Chris Kleponis

All European countries have refused to get involved. They blame the Middle East tensions on Trump’s decision to abandon a 2015 deal on Iran’s nuclear program under which facilities were monitored by international inspectors. The US imposed harsh economic sanctions, prompting threats from Iran to re-start the production of highly enriched uranium resources.

Washington obviously needs an ally, and Trump thought he had found one in Morrison. He praised Morrison as “a man of real, real strength”, but it was apparent Australia’s leader was more interested in words, not action.

The dilemma for Morrison is that Trump’s administration has been mostly bad for Australia, which has been buffeted by trade tensions between the US and China and left high and dry by Washington’s pullout from the Trans-Pacific Partnership, a multilateral trade pact initiated by the Barack Obama administration which aimed to reaffirm US commitments to Asia.

Moreover, Australia is frustrated that Trump’s obsession with Iran is distracting him from pledges to reengage with Pacific islands as a balance against spreading Chinese influence. In this instance, Trump may be out of step with his own military, which wants a stronger alliance with Canberra.

In July, it was revealed that the Pentagon is secretly drawing up plans to spend $211.5 million on naval facilities in the north Australian city of Darwin, presumably to support the rotational detachment of marines that could be deployed either to the Pacific or to the volatile South China Sea.

Australian defense chiefs denied that any new facilities were planned, but reports suggest that the marines will be relocated to a commercial port being built outside Darwin. The US is known to be concerned that a Chinese company was granted a 99-year lease over the city’s existing port.

An Australian naval officer on patrol in a file photo. Canberra has agreed to jointly patrol the Strait of Hormuz with the US to secure oil shipping lanes. Photo: Twitter

American Defense Secretary Mark Esper said in August that he wanted to deploy ground-launched, intermediate-range missiles in the Asia-Pacific to deter China. Morrison quickly denied that any would be sited in Australia though there is speculation that could be part of the Pentagon’s longer-term plan for Darwin.

This was no surprise, as China is Australia’s key economic and trade partner. But it underscored the difficult decisions Morrison will have to make over Australia’s security alliance with the US. Trump has shown through his dealings with the North Atlantic Treaty Organization (NATO) that he expects total loyalty from allies.

The 1951 Australia, New Zealand and United States Security Treaty — now confined to Australia and the US — does not compel either partner to respond to a security request, but Australia has been the only country to support every American military operation since World War II.

Until now, it appears. Zack Cooper, a research fellow at the American Enterprise Institute, a think tank, said questions were being asked in both nations about the alliance’s future.

“Polling shows that Australians are worried about the Trump administration’s approach to trade and alliances. Also concerning are Trump’s transactional nature and his America First approach, which threaten to undermine longstanding US alliances in both Europe and Asia.

“Americans, for their part, are worried that Australia and the US are diverging on China,” he wrote in the Strategist, the commentary site of the Australian Strategic Policy Institute, a Canberra-based independent think tank.

Chinese and Australian flags ripple in the wind. Photo: Facebook

It may need reform, but most analysts believe Australia cannot afford to diminish its security pact with its closest ally, and may even need a full partnership as its defense capability is stretched by conflicting obligations in the Middle East and the Pacific, as well as an increasing Asian role including in the South China Sea.

A study released last month by the United States Studies Center at the University of Sydney called for a policy of “collective defense” that would enable the countries to meet the Chinese challenge by pooling resources.

“Australia needs to work with its friends — the United States is committed to maintaining a military presence and maintaining deterrence against possible Chinese aggression in Asia, but it can’t do that alone,” it stated.

The report also said Australia should pull out of the Middle East, where it has deployed naval, army and air force units since 2001. It noted that Canberra spent US$9.9 billion on operations in that region in 2001-2018 — mostly in Iraq and Afghanistan — against just $2.6 billion in the Indo-Pacific.

Morrison may yet turn out to be a man of action in his awkward dance with Trump, as he has chosen the tempo: do enough to keep the alliance healthy, but not so much that Australia becomes entangled in US policies or a new military adventure in Iran. Morrison will also be careful not to step on the toes of another ally, China.

“This Australia-US alliance will not bring the benefits Australia hopes for,” wrote Academic Yu Lei in an opinion piece in China’s state-run Global Times. “This will bring a long-term military and political confrontation between Australia and Asian countries.”