PRESIDENT REAGAN'S STRATEGIC DEFENCE INITIATIVE (usually abbreviated to SDI and more popularly known as ‘star wars’) is generally agreed to have one great merit, whatever its many drawbacks. Concern over the long-term implications of this initiative is said to have convinced the Soviet Union that it should return to the arms control negotiating table that it left so abruptly at the end of 1983.

The difficulty with viewing SDI as a ‘bargaining chip’ is that the President has not shown himself inclined to use it for bargaining purposes. For those who believe that this is all that the SDI is really good for, given the doubts over whether it will ever really lead to a workable defensive system, the risk is that instead of cashing it in for substantial Soviet concessions on offensive arms, President Reagan, by persisting with SDI, will provoke countermeasures of both the defensive and offensive variety by the Soviet Union, and so lead to the ruin rather than the revitalization of the whole arms control process.