The question was thrown into sharp relief by the revelation Islamist terrorists attempted a cyber attack on the London Olympics
Could World War Three start with the click of a mouse in a bedroom in Kabul or an anonymous office block in Beijing?
That is the terrifying question faced by the West’s intelligence agencies every day, and it was thrown into sharp relief by yesterday’s revelation that Islamist terrorists attempted a cyber attack on the London Olympics.
They planned to disrupt the opening ceremony and possibly scupper the entire event by tampering with the electrical power systems at various stadiums. Luckily, they were thwarted by the UK’s increasingly sophisticated and well-resourced cyber security effort at GCHQ.
A blacked-out Olympics would have been embarrassing and annoying rather than catastrophic but it gives an insight into the power of cyber warfare and the ambition of some of its would-be practitioners.
Could ambitious terrorists start World War Three by launching electronic attacks? Well, yes, they could, in theory, up to a point.
If terrorists, say, gained control of the computer systems behind the UK’s nuclear deterrent and managed to fire off a Trident missile at Russia, then Russian radar systems would alert the Kremlin and President Putin would launch his retaliation immediately – no questions asked.
But frightening though this scenario sounds it would actually be far more difficult to accomplish than it looks.
Many military computers used to be fairly easy to hack into.
In 2002 Gary McKinnon, the Scottish systems administrator and hacker, played merry hell with a number of US military computer networks.
But security has since improved dramatically. The most sensitive computers in advanced countries are usually protected by an “air gap”.
In other words, they are part of a closed system cut off from the rest of cyberspace. There is no electronic connection to the outside world.
A clever hacker like McKinnon cannot find a way in, because there isn’t one.
Ironically, this was the kind of cyber-security practised by Osama bin Laden in his hideout at Abbottabad in north east Pakistan.
Bin Laden had no phones and no internet connection.
If he wanted to communicate he would draft a message on his computer offline, download it on to a thumb drive and get one of his helpers to send the message from a cyber cafe.
Replies were received in the same way. There were no electronic footprints leading to bin Laden.
The procedures for firing British Trident missiles are, of course, surrounded by secrecy.
Most people assume it involves the exchange of complicated codes from the “launch authority”, the Prime Minister.
But in fact it has been suggested that the instruction to launch would actually be issued to naval headquarters on a video-link by the PM in person.
There are some good Cameron mimics but this comparatively low-tech procedure acts as a final safeguard.
It might be a tiny bit easier to take control of the computer systems of a nuclear power station and try to make one blow up.
After all, Western intelligence agencies managed to introduce the Stuxnet virus into Iran’s uranium processing centrifuges, giving them the equivalent of an electronic nervous breakdown.
This might prove attractive to a certain type of terrorist, but it would be unlikely to set off a world war.
There is one part of the world though where a cyber attack could indeed set off a world war – South East Asia – where an increasingly competitive and suspicious United States and an increasingly assertive and ambitious China are limbering up to be rivals.
President Obama has deliberately tilted US defence policy away from Europe and the Middle East to refocus on the Pacific.
The US has offered military protection to countries such as Australia which are fearful of Chinese expansionism.
From next year, there will be a sizeable force of US Marines based in northern Australia. China is rapidly building its military strength – launching its first aircraft carrier, the must-have accessory of military power in the Pacific, earlier this year.
It wants a blue-water navy to rival the US. Aware of the difficulties of running large carrier fleets effectively, the Chinese have set up a number of naval academies.
But everyone who wants to join the Chinese Navy has one thing in common – they all study the Japanese surprise attack at Pearl Harbor.
Americans fear surprise attack.
Relations between the US and the Chinese leadership are not warm. The language and cultural barriers are difficult to overcome. The US is highly suspicious of China’s much vaunted cyber-warfare capability.
Islamists have little time for the Han Chinese who are seen as the oppressors of the Muslim Uighur people who live in the far west of China.
They have even less for the US. What better way to take out two enemies at once than by starting a military conflict in the Pacific?
Conduct a sophisticated cyber attack on a US carrier group in international waters in the South China Sea.
Persuade its commander it is under attack from a Chinese Dong Feng anti-ship missile, fired from a Chinese Navy flotilla and you’ve got a fake electronic Pearl Harbor.
There won’t be time for the American admiral to check with Washington before launching his own counter-attack.
The terrorists sit back and watch the sparks fly.
Crispin Black is an espionage expert and former government intelligence adviser