Chinese espionage, especially cyber espionage, has reached extraordinary levels. ''They're stealing everything that isn't bolted down and it's getting exponentially worse,'' says Mike Rogers, chairman of the US permanent select committee on intelligence, in a report just released by Bloomberg.

Richard Clarke, former cyber security adviser to the White House, says China has been ''hacking its way into every corporation it can find listed in Dun and Bradstreet''. This theft of commercial intellectual property constitutes the greatest illegal transfer of wealth in history, says Scott Borg, director of the US cyber consequences unit.

We should be taking note of this in Australia for all sorts of reasons. Chinese hacking is targeting Australia and the United States, and there are national security as well as economic implications. Moreover, it is not only cyber espionage of which we need to be wary. High-level Soviet moles operated in this country during the Cold War and they have yet to be exposed.

We are even more vulnerable to Chinese espionage now than we were to Soviet espionage then. It's time this hidden history was made public, if only to put the problem of Chinese (and revitalised Russian) espionage into sober perspective for an Australian public too given to complacency or cynicism in such matters.

Thirty years ago, in The National Times, Brian Toohey wrote about Soviet operations in Australia, based on an extended interview with CIA operations veteran Ted Shackley. His opening paragraph was stunning in its implications: ''The Soviet intelligence service, the KGB, has been more successful in its penetration operations in Australia than in any other country, according to hard evidence available to the American Central Intelligence Agency. The long standing CIA assessment is that the KGB has planted a mole in a key position in Canberra - probably high in the Foreign Affairs, Defence or the Prime Minister's Department.''

The CIA's hard evidence, Toohey wrote, had been built up over many years from both human and electronic sources. It demonstrated that the KGB had for years ''been able to obtain a much higher level of classified information from Canberra than anywhere else''. This was especially significant because much of what was obtained was sensitive intelligence shared with Australia by the United States.

Yet, as of 1981, the CIA had been baffled in trying to establish who exactly the Soviet mole or moles in Canberra were. Between 1993 and 1995, two highly secretive investigations, Operation Liver and the Cook inquiry, were conducted for the Keating government.

The investigators concluded that there had, indeed, been high-level, long-term penetration by Soviet intelligence, but the federal government has kept their findings under lock and key.

It's high time they were unlocked, because they provide an insight into the danger now presented by China, which is far better placed than the Soviet Union was to plant moles and agents in Australia.

China is a huge trading partner of Australia, which the Soviet Union never was. It is ascendant at a time when the United States is floundering in economic and strategic terms. And, despite its sinister communist past and the ongoing ruthlessness of the communist regime there, it cultivates a ''Middle Kingdom'' mystique.

Only a few well-placed people need be seduced for very serious damage to be done to our national security.

In his new book Tiger Trap: America's Secret Spy War with China, David Wise fills in the deeper background behind the Bloomberg report. The book places recent developments in the context of ancient Chinese traditions of espionage going back to Sun Tzu. It shows that Chinese espionage has grown relentlessly in the past few decades, even as many of us came to see China as a reformed totalitarian state with a market economy and a growing stake in global order. It describes the structure of the Chinese intelligence agencies, their modus operandi and their recent strategic successes against the United States.

Wise tells, for example, of Chinese acquisition of the top-secret technology for the W-88 nuclear warhead for the missiles carried by the Trident submarine, stealth technology for fighters, and a great deal more from the high-tech sectors of the American economy and defence sector.

Even more disturbing is that the spies who are supplying this technology to China remain mostly undetected. A four-year investigation, from 1999 to 2003, by a veteran counter-intelligence officer, Stephen Dillard, was unable to pinpoint the source of the W-88 breach.

As with China's relentless military build-up, there will be those who'll say, ''Well, they're not doing anything the Americans aren't doing, so who are we to complain?''

That is to forget where we stand in the world and where our interests lie. We are a key ally of the United States; it is the bastion of our own strategic security; we depend on it for cutting-edge military technology; we house major joint facilities on our soil; we have a new agreement for increased US presence here; and China's rising power and aspirations are, by regional agreement, the major uncertainty in Asia-Pacific stability for as far ahead as we can currently see.

Dr Paul Monk is a former China analyst with the Defence Intelligence Organisation and author of Thunder From The Silent Zone: Rethinking China.