To view a large version click on the image above.

What is the origin of the millennium bug?
Programmers in the 1960s decided to conserve computer memory by using only two digits to designate the year in computers’ internal clocks, with the first two digits assumed to be 19. Unless corrected, microchips and systems may misinterpret year 2000 as 1900 and malfunction. The latest estimates expect at least two per cent of all microchips to malfunction when the date rolls over from 99 to 00.

What kind of computers are vulnerable?
The Y2K (Year 2000) problem primarily affects two kinds of equipment: mainframe computer systems run by big institutions or businesses; and microchips, or ‘embedded processors’. There are an estimated 15 billion microchips worldwide, embedded in everything from smoke detectors to sewerage systems, alarms to automobiles.

The essence of the Y2K flaw is that it is unpredictable. It could make a computer stop dead or it could cause havoc by producing invalid data which is not immediately detected. (Watch your pay packets carefully over the next year...) The failure of just one chip can set off a chain of events, bringing down whole systems.

Do nuclear weapons rely on computers?
Nuclear weapons and their associated command, control and communications systems are completely dependent on computers and microchips. The US and Russia in particular monitor each other using interdependent radar, satellite and communications systems. The weapons themselves use millions of microchips, and over the years the military has tried to reduce costs by using ‘commercial-off-the-shelf’ chips (COTS) which may well be susceptible to the Y2K problem. The only way to make sure a system is Y2K compliant is to check it laboriously line by line, chip by chip.

But surely that’s what the military are doing, aren’t they?
They have been trying but failing. The US Naval Audit Service admitted on 4 January this year that ‘the Strategic Systems Programs will not meet the Department of Defense and Navy Target Completion Dates for their mission support and infrastructure.’ According to Brookings Institute analyst Bruce Blair, two systems, which are the primary mode of communications with ballistic missile submarines, will not be Y2K compliant by the turn of the century. As of June 1999 264 mission-critical systems in the US Department of Defense are still not yet Y2K compliant.

Why on earth can’t they get it together?
They’ve got huge problems. Much of the software currently in use is based upon virtually extinct programming languages that hardly anyone understands any more. The subsystems they have to test are so numerous and varied that they may not even be able to locate them. And even when they do, the microchips may have a date-specific program written into them that can’t be amended. Dry-run testing all systems and sub-systems in every conceivable scenario is fantastically time-consuming.

But if they’d checked it all we’d be safe?
Even if the military systems were completely error-free we would not be out of the woods. Any interface with another system could introduce bad data and wreak havoc. For example, US communications from Strategic Command to its nuclear submarines in the Mediterranean travel partly over the Italian telephone system.

Could a computer failure automatically launch a nuclear missile?
Unlikely. Most nuclear missiles have built-in security systems to avoid accidental launches. The missile would probably disable itself.

So what’s the problem?
If the military computer systems collapse there could be false early-warning information or a blank-out, leaving both sides ignorant of what the other is doing. A malfunctioning system could wrongly suggest that an enemy missile had been launched and cause a commander to authorize a missile launch in response.

This almost happened on 3 June 1980 when US nuclear command centres showed that Soviet missiles had been launched. Bomber crews started their engines and Minuteman missiles were readied for launch. Technicians recognized this as a false alarm only just in time. The malfunction was traced back to the failure of one microchip costing 46 cents.

But that was during the Cold War...
US insistence on retaining the right to launch a pre-emptive strike has led Russia to overturn its previous policy of ‘no first use’. Both Russia and the US have a policy of launching nuclear missiles ‘on warning’. Missiles are kept on high-alert status in order that they could be fired as soon as an enemy launch was detected. Of the 36,000 nuclear weapons remaining in the world 5,000 sit in silos on high-alert status. These missiles can be fired in about 15 minutes and reach their target cities in another 30 minutes.

But surely missiles are no longer targeted on foreign cities?
It is true that all the main nuclear powers (the US, Britain, France, Russia and China) have agreed to stop targeting ‘enemy’ cities. But retargeting would only take ten seconds. And in the event of a computer malfunction, some experts argue that a missile could revert to its last targeting instructions.

Aren’t most nuclear weapons carried on submarines these days?
Yes, and these submarines, powered by nuclear reactors, are completely dependent on computers, unable even to raise a periscope without them. In one recent case involving a British Trident submarine, the nuclear-power plant was accidentally turned off and the submarine started to plummet to the ocean floor. Luckily, the reactor was turned back on before the submarine imploded from the pressure of being beyond its maximum design depth. But if Y2K problems caused the glitch there might be no way of restarting the reactor.

You only mention Britain and the US. What about other nuclear powers?
There is worryingly little information about their nuclear checking. But what there is suggests India, Pakistan, Israel, France and China are way behind the US and Britain in their preparations for the general Y2K problem, with China and Pakistan lagging farthest behind. US intelligence sources testified to Congress: ‘Its late start in addressing Y2K issues suggests Beijing will fail to solve many of its Y2K problems in the limited time remaining, and will probably experience failures in key sectors such as telecommunications, electric power and banking.’ But China is less of a worry because it does not keep its nuclear weapons on high alert and has a ‘no first use’ policy.

What about Russia?
Until February 1999 Russia was denying that its nuclear forces could face Y2K difficulties. But according to Russian scientists now working in the US, the financially starved Russian military and its antiquated computer systems are bound to be prone to failure. Since then Russia has acknowledged it has a problem and asked for financial and technical assistance. The chair of the State Communications Committee, Aleksandr Krupnov, said recently: ‘Who knows if the country will be ready? I can’t give any guarantees.’

The most worrying element is Russia’s nuclear control system, called ‘Perimeter’. According to Jane’s Intelligence Review, if Moscow looked like it was under attack, or even if command links to key Russian leaders were interrupted, Perimeter would automatically launch a communications missile that would in turn transmit the codes to launch thousands of nuclear weapons.

But surely if the US and the Russians know about the Y2K problem they will realize any warnings on New Year’s Eve are likely to be false alarms?
The two countries were laying plans for a jointly operated early-warning centre that might help this. But when war in the Balkans broke out Russia broke off co-operation on this. Besides, 1 January 2000 is not the only date to worry about. There are other dates on which systems could malfunction.

Such as?
Such as 21 August 1999, when the internal clock of the Global Positioning System (by which the world now measures time, using signals from satellites) will roll over to include the year 2000, with possible calamitous results for any country whose satellite receivers haven’t been properly configured.

So what do we do?
Go to the Action Section to find out.