Is World War III brewing over South China Sea?

With tensions flaring between the United States and China since the election of Donald Trump, strategists are grappling with the prospect of a war between the two nuclear powers.

The disputes over the South China Sea, threats of a trade war, and relations with Taiwan are all contributing to speculation of an impending conflict, says News.com.au.

A US ex-marine and defence expert now claims the Trump administration will effectively foil China's territorial ambitions.

He claims there is a massive ''miscalculation'' in Beijing's set-up in the disputed region, arguing that the Trump administration's aggression will ultimately thwart China's claims to the region.

As Trump's administration continues to provoke the Chinese government, other experts have gone as far as to suggest it could be the onset of World War III.

Grant Newsham, a former US Marine Officer and senior research fellow at the Japan Forum for Strategic Studies, says Beijing has backed itself into a box.

Writing in the Asia Times, he says China underestimated the extent to which the new White House administration will go to stop it, and that their geographical set-up in the disputed region will work against them.

Chinese military planners have placed great control on a chain of islands running from the Kuril Islands, near Russia, down to Borneo and the northern part of the Philippines.

This is referred to as the ''First Island Chain'', seen as Beijing's primary defence line against interventionist forces. The idea is to seal off enemy forces from within this arc, and block them from being able to combat China's territorial aims.

''China's strength inside the First Island Chain may not be the strategic advantage it seems,'' said Newsham.

''Regional geography is an unchanging variable and not in China's favour in this case as it leaves open the possibility that if push comes to shove the US and its partners could hem Chinese forces inside the First Island Chain. And if necessary, make life exceedingly difficult for Chinese forces operating inside the chain.''

He says there are very few access and exit points through the chain, which can be covered and blocked using a combination of weapons.

He also says there's nothing to stop weapons from the US and its allies from reaching ''well inside'' the First Island Chain, which would effectively render Beijing powerless.

''President Xi and his immediate predecessors perhaps didn't think through the geography angle as much as they might have,'' says Newsham.

''For a scheme ultimately dependent on American acquiescence, Donald Trump's election threw a wrench into the works.''

In other words, China's plans were only going to work so long as the US kept out and let it quietly get on with expanding its aims.

And judging by remarks from Trump's close aides like Secretary of State Rex Tillerson and Trump himself, that no longer seems to be the case.

''China needs to decide if potentially taking on the full might of the United States - to include serious economic costs (which the US is capable of inflicting) - is worth the effort and the drain on resources of continuing its drive to dominate East Asia and international waters and ocean territory of other nations,'' concludes Newsham.

But whether the Trump administration will actually act on its threats and go after China remains the key question.

In the lead-up to the November election, Trump made very little reference to the South China Sea. It was understood he wanted to retreat America from the world stage, and the implication was he would focus his attention on domestic rather than global policy.

Tillerson, Spicer aggressive
But fast-forward to the week before Donald Trump's inauguration last month, and Secretary of State Rex Tillerson was voicing a tough stance against China's territorial aims in the disputed sea region.

He hinted at blockading the country's access to its artificial islands, with the purpose of forcing Beijing to roll back and ultimately abandon them.

The United States must ''send a clear signal that, first, the island-building stops'', he said, adding that Beijing's ''access to those islands is not going to be allowed''.

White House press secretary Sean Spicer reiterated Tillerson's threat after the inauguration.

Earlier this week, it emerged that Donald Trump's chief strategist Steve Bannon warned China and the US will go to war within the next decade.

In March last year, Bannon predicted during a radio show hosted by his far-right website Breitbart that the two countries would engage in war ''in five to 10 years''.

''There's no doubt about that,'' he said. ''They're taking their sandbars and making basically stationary aircraft carriers and putting missiles on those. They come here to the United States in front of our face - and you understand how important face is - and say it's an ancient territorial sea.''

The Chinese government has since downplayed the prospect of a blowout.

Meeting with Australian foreign minister Julie Bishop this week, Chinese foreign minister Wang Yi addressed the prediction with a subtle dig, saying that any ''sober-minded politician'' would understand neither side would engage in war.

He dismissed Bannon's words, saying ''irrational statements'' had often been made about US-Sino relations over the past 40 years.

Since Bannon's remarks of an imminent war emerged this week, speculation rose that this could be the beginning of World War III.

In an article called Backing Into World War III, posted on Foreign Policy, diplomacy commentator Robert Kagan said it's inevitable the world will ''slide into brutal anarchy'' as Beijing continues its spat with Washington.

''Early signs suggest that the new administration is more likely to hasten us toward crisis than slow or reverse these trends.

''The further accommodation of Russia can only embolden Vladimir Putin, and the tough talk with China will likely lead Beijing to test the new administration's resolve militarily.''

Trump has other worries
But not everybody thinks a global war of this magnitude is inevitable.

Macquarie University Security Studies analyst Dr Adam Lockyer told news.com.au the impression of the Trump administration muscling up to Beijing didn't necessarily mean action would be taken.

''They're saying so many provocative things on so many different fronts - domestically and internationally,'' he said. ''So it's difficult to see where Trump is going to invest his diminishing political capital.

''If he's going to assert freedom of the seas in the South China Sea, this will absorb political capital and a significant amount of White House attention.

''It could just be a case of him bolstering his image rather than assertive policy.''

The White House asserting power in the South China Sea would likely be counter-productive, he said, at least in terms of regional allies.

''If the US has the naval strength to go into the region and blow up China's artificial islands, there's not much China can do about it,'' he said. ''But that's going to put the entire region off-side.

''While some countries may feel quietly relieved, it won't endear the US with the Philippines, Vietnam, Indonesia and even Australia - we're deeply concerned about the process, because it would cement the US as a revisionist power.''

Australia jittery
Dr Lockyer, who just published a new book on the subject called Australia's Defence Strategy: Evaluating Alternatives for a Contested Asia, stressed that a war between the two powers is the last thing Australia would want, given its crucial trading ties with both countries.

That said, it's highly unlikely a theoretical conflict would be comparable with World War I or II.

''For that kind of conflict to happen, someone would need to put troops down on the ground somewhere,'' he explained.

''The Chinese aren't going to bait the US and vice versa. This would be a war fought in the air and fought at sea - it wouldn't last for six years. It would heat up and then picker out.''

Last week, former head of the Australian Defence Force (ADF) Sir Angus Houston said China's presence in the disputed region was permanent.

''In my view it is too late to stop the China program in the South China Sea,'' said Sir Angus at a conference in Canberra. ''What is important now is to ensure freedom of navigation and the right of innocent passage.

''I have seen the imagery (and) what you see is infrastructure going in, and it is not going to be too much longer before it is fully developed.

''All of this development will enable China to dominate the South China Sea and extend its permanent military presence further south in proximity to Indonesia, Malaysia and Singapore.''