HC Deb 03 April 1962 vol 657 cc205-8
Q1. Mrs. Castle

asked the Prime Minister what recent representations he has made to President Kennedy regarding the resumption of the United States atmospheric tests before another attempt has been made to reach agreement with the Union of Soviet Socialist Republics at a summit conference.

Q2. Mr. A. Henderson

asked the Prime Minister whether he will consult President Kennedy on the feasibility of both the United States and the United Kingdom Governments accepting a test ban agreement based on a national control system of all tests with provision for international verification in cases of dispute.

The Prime Minister (Mr. Harold Macmillan)

I am, of course, in constant communication with President Kennedy on these matters, but this must be confidential if it is to be useful. While the Disarmament Conference is meeting at Geneva, I would prefer not to enter into a discussion about particular proposals. But, as the House knows, the Russians have so far rejected any form of verification within the Soviet Union. I have at present nothing to add to what I have already told the House.

Mrs. Castle

Is the Prime Minister aware that the hopes of some of us were raised by reports that Her Majesty's Government were bringing pressure to bear on the United States Government to postpone their atmospheric tests until after a summit conference had been held? Does the right hon. Gentleman's reply mean that those reports are not true? Is it not the fact that in the Disarmament Conference the neutral nations have been pressing for this course of action, and ought we not to be supporting them?

The Prime Minister

The neutral nations have been discussing this matter in full at the plenary session, and it has been discussed, of course, in the sub-committee. I have nothing at present to add to what I have already told the House

Mr. A. Henderson

In view of the recent statement by the Soviet Foreign Minister that it is now possible for national monitoring to take place of all nuclear tests, would the Prime Minister consider publicising the views of British and American scientists on that statement? Is it not of vital importance that public opinion should know exactly what is scientifically possible in this sphere?

The Prime Minister

It is, of course, true that certain advances have been made, but I think that that statement is much too general. However, the real point is that some system of verification—whatever be the system of first finding out a complaint—is necessary in order to prove or disprove what might be alleged by a national system of inquiry.

Mr. Gaitskell

Can the Prime Minister say whether it is his opinion that effective international verification does require control posts on Soviet territory, whether manned by American and British teams or by neutral teams?

The Prime Minister

In the present state of science, yes, Sir. I do not think that that would necessarily be always the case. It is a very complicated scientific problem, but the real difficulty is, as I have said, that wherever the control post was, whether in Soviet territory or outside, it would make what might be called a prima facie case that an explosion had taken place that was unexplained. There must be some system of verification in order to make the treaty effective.

Mr. Gaitskell

I am sure the Prime Minister appreciates—or does he appreciate?—that there is a distinction between insisting that the control posts in the Soviet Union should be manned by representatives of Britain and the United States and that they should be manned by representatives of neutral countries. Does the West object to representatives of neutral countries being there, or is it merely a question that there must be control posts in the Soviet Union?

The Prime Minister

Well, Sir, I think that we have tried this in all possible ways. I think that the last thing I saw was that Mr. Dean Rusk suggested that the verification teams should be neutral, as well as having neutrals if there were control posts. The trouble is that over and over again we simply got the same answer: the Soviet Union will not agree to any system of verification which involves even a visit to Soviet soil.

Mr. Mason

Can the Prime Minister say what is the advice now available to him from our nuclear scientists? Is it not possible to detect all nuclear tests, whether made underground, underwater, in the atmosphere or in the stratosphere?

The Prime Minister

No, Sir. That is not at all possible. This is a very complicated matter, and I do not want to get into great detail about it, but what is possible underground is to know that some oscillation has taken place. It is a very difficult matter for the instruments to know whether that oscillation is due to a natural or to an unnatural cause. It is a question of the difference that may be shown in the waves. It may show a suspicion, but the point is that if that suspicion is revealed, wherever the posts may be, there must be some verification to prove or disprove the allegation of a breach of the treaty.

Mr. H. Wilson

Will the Prime Minister at any rate confirm that it is now possible to get full verification from outside in respect of atmospheric tests—and, possibly, in respect of underground tests—from about one kiloton upwards, or whatever the figure may be; that atmospheric tests may be verified? Would the right hon. Gentleman bear in mind, though it would be a very poor second-best, that an agreement on atmospheric tests would be a very big step forward? Would he, in studying this question—and we understand that he cannot say too much while negotiations are going on—also bear in mind the suggestion contained in the last few words of my right hon. and learned Friend the Member for Rowley Regis and Tipton (Mr. A. Henderson) that there might be national monitoring, but that where there is a dispute there must be a visit from, perhaps, a group of neutrals?

The Prime Minister

I can only repeat that we are trying to make all kinds of new suggestions in the hope of moving the Soviet Union from its present position of, "No form of verification of any kind on Soviet territory." But I could not accept the right hon. Gentleman's second point that national tests can verify nuclear explosions underground up to one kiloton, or even up to 5 kilotons. They cannot. They can verify that an oscillation has taken place. The problem is to decide the cause of the oscillation, and that varies very much at different ranges. It is a very complicated question. It is, curiously, worse at a moderate range than at either a near range or a very distant one. But it is quite an important point.

With regard to the right hon. Gentleman's first point, atmospheric tests can certainly be verified, unless they are at a very great height, when they could only be verified, possibly, in an international way, or by some aeroplanes which would have to pick up the results. If the tests were 100 miles up, or something like that, they would not be the atmospheric tests about which we have been talking.