The escalating threat of "grey zone" warfare

Australia is battling the escalating threat of "grey zone" warfare from China and other powers that risks becoming outright conflict, a security expert has warned.

Nigel Phair, of the University of New South Wales Canberra Cyber, told nine.com.au that a warning by a senior Australian general revealed today is a timely reminder of a largely unseen mode of aggressive action the country is facing.

Major-General Adam Findlay gave a confidential briefing to Australia's special forces soldiers last year warning of a high likelihood of conflict, The Sydney Morning Herald has reported.

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General Findlay identified China as the biggest regional threat and said Beijing was already engaged in "grey zone" warfare against Australia.

The grey zone includes cyber attacks and disinformation campaigns and falls short of an actual shooting war.

But Mr Phair said it should still be regarded as a form of aggression.

"I take the cyber out of cyber warfare ... it's all warfare ... It is another theatre of conflict ... even though there are no planes in the sky or ships at sea," Mr Phair said.

"The grey zone is all about state craft and furthering the ambitions of one power."

Democracies such as Australia were catching up with authoritarian regimes such as China, North Korea, Iran and Russia which were the first nations to use grey warfare.

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But Mr Phair said Australia had the technological muscle to hit back and "throw some sand in the gears" of its cyber adversaries.

"Former prime minister Malcolm Turnbull's national cyber security threat in 2015-2016 was very important," Mr Phair said.

"We do have the capability to hit back now - but it must be proportionate and in accordance with international law."