§ Lord Mayhew
asked Her Majesty's Government:
Whether a Trident submarine could be used, if necessary, in a sub-strategic role.
My Lords, Trident is a strategic system. NATO's new strategic concept approved at the Rome Summit in November 1991 made clear that sub-strategic forces are an essential link between conventional and strategic forces. There are many technical and operational reasons for not relying on Trident to discharge sub-strategic roles too.
§ Lord Mayhew
My Lords, will the noble Earl confirm that Trident could have many advantages? Does he agree that it is less vulnerable than air-to-surface systems; it is probably more accurate; and if it could combine the two roles it would save the country well over £2 billion?
My Lords, the reason why the Government disagree with that view can be summed up in two words: flexibility and security. If we were now to rely solely on submarine-launched systems we should be putting all our nuclear eggs into one basket for decades ahead. A separate capability is a hedge against the possibility of unanticipated technical or operational advances which could threaten Trident's capability. Advances in anti-submarine warfare techniques are one example.
§ Lord Mellish
My Lords, will the noble Earl confirm that Trident is a minimum deterrent? Does he agree that it is to the credit of this Government and the nation that we continue to rely on nuclear deterrents while the world is in its present state?
My Lords, I agree with the noble Lord that this is a highly uncertain world and that it is the task of the Government to plan for the long term.
§ Viscount Mersey
My Lords, does the noble Earl agree that with the variable yield warhead the Trident missile could indeed be regarded as sub-strategic? How can one measure sub-strategic by any means other than by the size of the explosion?
My Lords, the best way to describe what we mean by a sub-strategic strike is that it would be a measured but unmistakable warning in the face of aggression against us that we were unwilling to yield. The aim would be to induce an enemy to end his aggression to ensure his continued survival. That is very different from an all-out strike.
§ Lord Molloy
My Lords, does the noble Earl agree that at present there is a possibility that the breakup of' the USSR has created a more dangerous situation than when the Soviet Union existed? Does he further agree that we therefore have to be cautious and give great thought to any changes made in any form of our armaments?
My Lords, I fully agree with the noble Lord. Control over a nuclear arsenal is only as good as the commitment and dependability of the forces which guard it.
§ Lord Williams of Elvel
My Lords, will the noble Earl agree that his definition of a sub-strategic strike lends credence to the idea that Trident could be used in such a capacity if necessary? That is not to say that there should not be a strategic role as well. But if a sub-strategic strike is to deter a possible aggressor with a limited strike, could not Trident do that perfectly easily?
My Lords, Trident is a system designed to fulfil a strategic role. The Government fully subscribe to NATO's policy of maintaining separate sub-strategic forces in Europe.
§ Lord Mayhew
My Lords, is the noble Earl aware that a previous Answer on this subject showed that the Government regard Trident as extremely flexible and quite capable of firing not only a single missile but a single warhead from a single missile? Is he further aware that the arguments that it cannot use the sub-strategic role are not satisfactory?
My Lords, doubtless a missile of any kind could be launched from a submarine, but that is not the point. The Government believe that it would be unwise to rely on the noble Lord's premise as the basis for the country's defence in time of war.