Shield would put further strain on Moscow's decaying defences

Russia feels threatened by the planned American missile defence shield because the country's capacity to defend itself is declining. Recent embarrassing accidents have underlined Moscow's inability to maintain hi-tech weapons, including those needed to detect and counter a nuclear attack.

One of the most modern weapons in the Russian arsenal is the S-300, a surface-to-air missile, which it is eagerly marketing to foreign customers. The weapon has a range of 120 miles and can be used against aircraft or incoming missiles.

A battery of them had been stationed near the village of Zakharovo on the outskirts of Moscow. Last week villagers saw clouds of black smoke from the base. A military spokesman said a short-circuit in a missile engine had ignited the rocket fuel. Twelve S-300s were destroyed. On 10 May, Russia lost contact with four of its military satellites, backbone of its early warning system against nuclear attack. The cause was again a short-circuit, which caused a fire in a relay station at Serpukhov, 130 miles south-west of Moscow. The station burned easily because it was wooden.

The decay of Russian defence systems, after more than a decade of under-funding, puts in doubt a central argument used by President Bush in support of national missile defence (NMD) and against the ABM treaty of 1972. This is that the nuclear balance between Russia and the US is stable and a defensive shield would only be useful against "rogue states".

But the recent disastrous fires ­ as well as the sinking of the nuclear submarine Kursk last year ­ underline the extent to which Russia's economic decline is eroding the country's ability to field a credible nuclear deterrent. Out of 350 mobile nuclear missiles the Strategic Rocket Forces can only deploy only nine to covert locations, says Dr Bruce Blair of the centre for defence information in Washington. The Russian Navy can keep only one or two of its 26 ballistic missile submarines at sea.

The danger of NMD from the Russian point of view is that the shield's ability to provide real defence for the US may look limited today. But the number of Russian nuclear missiles is falling. They cannot be replaced because there is no money to pay for them. Some 76 per cent of the 90 Russian satellites in orbit ­ half of them military ­ are close to the end of their working life says Yuri Koptev, the head of the Russian space and aeronautics agency.

This means that in 10 years even a partially effective NMD might change the nuclear balance between Moscow and Washington. Unfortunately Russia is likely to respond to this growing military weakness by putting its nuclear forces on hair-trigger alert. This increases the danger of an accidental launch.

Such accidents have come close to happening. In 1995, Nasa, the US space agency, launched a scientific research satellite off Norway. Russian radar mistook it for an incoming nuclear missile. President Boris Yeltsin started a nuclear countdown for Russia to launch its own missiles. Recognising the danger of an accidental Russian nuclear attack based on misinformation from its early warning systems Moscow and Washington agreed in 1998 to share information on missile launches.

A base outside Moscow was to be manned by US and Russian officers. But Russia wants the US contractors to pay taxes. They refuse because the US is providing the $7m needed to build the base. Nothing has happened.