Indonesian President Joko Widodo has announced he will raise the “very important” prospect of joint naval patrols with Australia in the South China Sea during a state visit to Sydney this weekend.

It is his first visit to Australia since being elected in 2014.

But the idea has prompted a warning from former Australian Defence Force chief Sir Angus Houston, who said we should avoid supporting any move to blockade Beijing’s controversial artificial island fortresses being build throughout the strategic Asian waterway.

The ports, airfields, barracks and anti-aircraft defences are being built in defiance of international law in an effort to enforce sovereignty over seas also claimed by Malaysia, Philippines, Vietnam and Indonesia. More than $5 trillion in trade passes through the area each year.

“In terms of the question about freedom of navigation within the 12-mile limit, I don’t think we need to do that, I think that could provoke a military response and I don’t think that would be a good idea,” he told the National Press Club.

His comments followed a call earlier this week by US Admiral of the Pacific Fleet Harry Harris for a stronger response to Beijing’s island-grab.

“(We’ll) co-operate where we can, but we’ll be ready to confront where we must”, he said.

“We’re approaching an inflection point in history ... We’re certainly not approaching anything resembling the end of history.”

LENGTHENING SHADOW

At stake in this weekend’s talks is Indonesia’s ownership of waters generally regarded as being outside the southern boundaries of the South China Sea.

Indonesian and Chinese vessels clashed repeatedly in waters around the Natunas Islands last year after Beijing asserted it was part of its traditional territory.

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Indonesia considers the islands — and the valuable fishery and natural resources around them — as its own sovereign territory.

“If there is no tension I think it’s very important to have patrols together,” Widodo told The Australian. “We will discuss this with PM Turnbull.”

The request comes shortly after Beijing demonstrated its growing military reach.

The People Liberation Army reported a task force of three ships, including two advanced guided missile destroyers and an underway replenishment ship, passed through Indonesia and into Indian Ocean waters between it and Australia.

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The task force conduced military exercises near shipping lanes in Australia’s maritime approaches.

The ships went on to complete similar manoeuvres in the South China Sea shortly before the arrival of a US aircraft carrier battlegroup earlier this week.

RHETORIC RISING

One of the United States top military commanders in the region, Admiral of the Pacific Fleet army Harris, told a conference earlier this week that the Asia-Pacific region faced four challenges to its security:

North Korea, China, Russia and Islamic State.

On the South China Sea, Admiral Harris said the United States would not let the shared assets and waterways there to be shut down.

Beijing has created seven island fortresses in the Spratly Islands in recent years, built up from islets and reefs. Their claims that these artificial islands represent sovereign territory was ruled illegal by an international court of arbitration last year.

“Freedom, justice and the rules-based international order hang in the balance and the scale won’t tip of its own accord or simply because good people wish it so,” he said.

“They (Beijing) can choose to disregard the rules-based security order that has served all nations — including them — so well for decades or they can contribute to it as responsible stakeholders.

“I hope for the latter, but I have to be prepared for the former.”

Working with allies in the region — including Australia — will help the US “beacon of light” continues to “shine” and allow “good to overcome evil”, he said.

“Our country must maintain credible combat power, in concert with like-minded allies and partners, to preserve unimpeded access to all the shared domains — sea, air, land, space, and cyber,” he said.

ALL THE WAY ... WITH TRUMP?

“In terms of ... the idea of blockading the islands, I wouldn’t support that,” former defence chief Sir Angus Houston told the National Press Club. “I think that will invite a sharp response from the ­Chinese.”

He has previously said it is already “too late” to stop Beijing from taking ownership of the South China Sea.

But the idea of just such a blockade has reportedly been bandied about in President Trump’s innermost circle of advisers.

Current Secretary of State Rex Tillerson said last year that the US would possibly “stop” China from accessing their artificial islands.

And the idea has gained renewed momentum with news that missile and gun emplacements on Beijing’s South China Sea artificial islands — first spotted in December — are now nearing completion.

According to images published by the Asia Maritime Transparency Initiative, the structures are being installed on Fiery Cross Reef, Mischief Reef and Subi Reef in the Spratly Islands.

“This indicates they are not reactions to the political cycle in Washington, but rather part of a steady pattern of Chinese militarisation,” the Asia Maritime Transparency Initiative think-tank states.

The weapons appear designed to protect extensive military-grade, armoured hangars and airfield installations.

Defence analysts fear it is only a matter of time before a force of fighters, bombers and surveillance aircraft are deployed to the islands to enforce Beijing’s claims over the surrounding waters.

FRIENDS IN NEED?

Ties between Indonesia and Australia have been rocky in recent years.

The execution of Australian drug smugglers and Canberra’s policy of turning back asylum seeking boats has resulted in repeated outbursts of heated rhetoric.

But China’s growing ambitions may draw the two neighbours closer together.

Relations took an upswing in 2015 once Prime Minister Malcolm Turnbull took office. But it experienced fresh strains last month when Indonesia suspended military co-operation with Australia over allegations of ‘offensive’ training materials being found at an Australian army base.

The idea of a joint patrol, however, is being touted as a demonstration of our closer ties.

“This visit is very important for us because it shows how close we are as neighbours,” Indonesia’s foreign ministry spokesman Arrmanantha Nasir said.

In response, Prime Minister Turnbull said that the “bilateral relationship with Indonesia is vitally important to both countries and has never been stronger”.

President Widodo had originally planned to visit Australia, but civil unrest in Jakarta forced its cancellation.

He will be in Sydney on Saturday and Sunday for the state visit, accompanied by several cabinet ministers. Prime Minister Turnbull will also hold a private dinner with the Indonesian leader and his wife.