Leading article: China and a premonition of combat by other means

The Pentagon, the German Chancellery, and now Whitehall. If we are to believe the reports of recent days, some of the Western world's most sophisticated computer systems have been infiltrated by Chinese hackers. And the supposed culprits are not just any old Chinese techno-geeks, but cyber-professionals in the pay of the Chinese government.

Such news, for which anyone outside the rarefied intelligence world has had scant preparation, prompts conflicting reactions. The first is panicked alarm that the world's next superpower is already dictating the terms of a future contest for global supremacy. The second is blind disbelief that a country at China's stage of development would be capable of mounting such hi-tech attacks, at least at state level. And the third is that, true or not, the flurry of reports says as much about Western fears, as it does about China.

Certainly, there is an element of paranoia in these allegations. The industrialised world has shown a fear of the genie it has conjured up in the new technology ever since computers became standard feature of every office. A multimillion-pound industry has grown up, promising protection from bugs and hostile hackery, which of course has no interest in playing such risks down.

The meteoric rise of China over pretty much the same time has fuelled concerns of its own, especially across the Atlantic. Successive Congressional reports have singled out China as the enemy of the future, cast aspersions on its political intentions and treated its commercial inroads into the US as the advance guard of a more comprehensive assault. All the popular stereotypes are resurrected: the Chinese as devious, clever, calculating and contemptuous of Western ways.

So the combination of China and cyber-power is a lethal one, playing to age-old occidental apprehensions. This does not mean, however, that reports of state-sponsored Chinese computer hacking should be dismissed. With similar reports coming from several major capitals, something is clearly going on.

Reading between the lines of the cautious official statements issued so far, what infiltration there has been seems to have been sporadic and limited: more in the way of exploratory than aggressive hacking. Unless the authorities are deliberately underplaying the dangers, there seems at this stage no reason for panic.

Any attempted foreign infiltration of government computers, however, must be taken as a warning – not only of other countries' intentions, but of what might be possible in future. The more advanced a country technologically, the greater its potential vulnerability. Every aspect of administration that is computerised can theoretically be interfered with or destroyed.

What happened in the small – and hi-tech – Baltic state of Estonia earlier this year illustrates the risks. It almost ground to a halt after its computers were swamped with mail at the height of a dispute with Russia. Estonia accused Russia of cyber-sabotage. Russia, as China now, denied it – but the assault bore all the hallmarks of a professional, if not demonstrably state-sponsored, attack on the country's ability to function.

The attractions of cyber-sabotage for countries that are relatively weak, politically or militarily, are obvious. Like terrorism, it is a form of asymmetric warfare that evens up the odds. You have only to think of a situation in which the banking system cannot move money around, the power grid is closed down and the mobile phone network is rendered inoperable to glimpse some of the possible effects. So far, this is the stuff of disaster movies. But every government has a responsibility to ensure, so far as possible, that it is not also a premonition of the future.