Australia, which claims to be neutral in the South China Sea disputes, has been taking actions that suggests otherwise.

The Balikatan annual exercise conducted by the US and the Philippines kicked off on Monday.

Australia has sent 86 military personnel, including 30 commandos from the second Commando Regiment, to the annual war games hosted by the two.

Prior to the exercise when Commander of the US Seventh Fleet Vice Admiral Joseph P Aucoin paid a visit to Australia in February for high-level talks with defense leaders, he urged Australia to carry out joint patrol with other nations within 12 nautical miles of disputed territory in the South China Sea.

Australian Defense Minister Marise Payne did not comment publicly on the specific details, but said Australia supported every country's rights to freedom of navigation.

Why did Australia, which is used to gaining advantages from both China and the US, choose to take a side this time?

The US has been perfidiously playing one side against the other. For a long time, Australia has maintained a firm alliance with the US and acted at the beck and call of the US in a number of international and regional affairs.

Due to Australia's geographic strategic position, its role in the Asia-Pacific has become prominent. As the US accelerates its rebalancing to the Asia-Pacific, it urgently needs Australia to play a more significant role in the South China Sea so as to shoulder more responsibilities.

In the past, the US government and military often expressed dissatisfaction with Australia, which had shown an ambiguous attitude toward the South China Sea disputes. The US has imposed pressure on Australia several times by sending marines, bombers and warships there.

Meanwhile, Australia has adopted a dual track approach. For years the bilateral relations between China and Australia have been going smoothly and their trade ties remain steady. China is Australia's biggest trading partner, and Australia has been highly dependent on China in its economic development.

The two countries have established strategic mechanisms of diplomatic and economic dialogues. They also have started direct clearing between the yuan and the Australian dollar.

But when security clashes with the economy, security has become prioritized by the Australian side.

In addition, the Chinese economy has slowed down in recent years and international mineral prices have plummeted, which has led to decreased export of minerals to China.

Therefore, Australia is less dependent on the Chinese economy and the economy is not as important as before in Australia's national strategy.

Australia boasts a vast area of 7.68 million square kilometers. In recent years, thanks to the sustained economic growth and upgrades of weapons, Australia has boosted its confidence as a regional power.

The South China Sea region, which is 2,000 kilometers far from the Australian soil, has become the place where it can display its ambition.

With the US as its backup and Japan encouraging it, Australia may act aggressively regardless of warnings from China.

China must send warnings to Australia, which is trying to meddle in the South China Sea disputes with the US. It can warn Canberra through political, diplomatic and public means. Meanwhile China should point out the selfish US mind-set in the South China Sea and once Australia falls into the orbit of the US, it may become its scapegoat.

When a crisis occurs, the US is an external player anyway, but Australia, which is in the Pacific Ocean, will be trapped in an unfavorable condition.

Although the Chinese economy faces downward pressure, Asia, including China, is still a region with the most vitality and best prosperity.

As a big power in the Asia-Pacific, it should be clear-minded that only regional cooperation can bring new vitality while frictions and disputes will create more troubles.

The author is a specialist in naval military affairs. opinion@globaltimes.com.cn Follow us on Twitter @GTopinion