But some experts believe the missiles have been 'de-targeted' or are already being re-targeted, some of them on Russia, although their minimum range would exclude many nearer targets, including Moscow.
Mr Christopher arrives in Ukraine tomorrow after stops in Russia and Kazakhstan as part of a tour of five former Soviet republics designed to secure destruction of much of the former superpower's nuclear arsenal.
In the last few days the Ukrainian President, Leonid Kravchuk, has said SS-24 missiles 'could be taken off military readiness and the codes aiming them at the US removed' so long as the US and other nuclear powers guaranteed their missiles would be taken off alert.
He said Ukraine 'could if it wanted have the technical capacity to target and launch the missiles', but had no plans to do so.
Ukraine has 120 SS-19 Stiletto missiles at two sites and 46 SS-24 Scalpel missiles in silos. Both systems have a maximum range of 10,000km (6,200 miles) and carry six and 10 Multiple Independently Targeted warheads, respectively. The SS-19s are liquid-fuelled, time-consuming and difficult to prepare for launch; the SS-24s are solid-fuelled.
An analysis in the forthcoming issue of Jane's Intelligence Review points out that all former Soviet missile guidance and control systems were produced in Ukraine, as is the necessary software, enabling the Ukrainians to develop ways of re-targeting the missiles even if the right tapes were not immediately available. In December 1992 Valentin Larionov, a well-known Russian military writer, reported the 'removal of targeting instructions from a percentage of our missiles'. And recently, a general in the Strategic Missile Forces reported the removal of cables, suggesting that Ukraine's missiles are probably aimed - nowhere.
The article explains that Soviet submarine-launched ballistic missiles are controlled by punched tapes produced by the Soviet (succeeded by the Russian) General Staff. Each tape contains the data for a particular target. These, and authorisation messages, would be needed before missiles could be fired. But even if in possession of tapes and authorisation, a submarine captain would not know where his missiles would land.
The article also says the SS-19 has a minimum range of 3,000km. From the Ukrainian border to Moscow is only a tenth of that distance, so many of the most obvious targets in western Russia could not be attacked. The Ukrainian government realises that the maintenance of a small nuclear force would be disproportionately expensive for a state struggling to establish itself and that in the event of a war with Russia - regarded by Western as well as Eastern analysts as a nightmare scenario - their use would be suicidal as Ukraine has no way of launching a 'second strike' in a nuclear war with Russia.
In May, top Russian sources said Ukraine was taking over control of the missiles on its territory and that the re-targeting process would take from eight months to a year. This squares with estimates by US experts like Bruce Blair, who estimated 'several months', and others who believe it could take 18 months.
Russian experts, the article says, believe Ukraine could re-target ballistic missiles if the Multiple Warheads of each missile were directed at a single point.
Ukraine, unlike Russia, Kazakhstan and Belarus, has yet to ratify the Start 1 (Strategic Arms Reduction Talks) treaty and protocols providing for Moscow to be the sole holder of former Soviet nuclear weapons following the collapse of Communism.Reuse content