The Secretary of State for Defence has attempted to reply to the devastating opening speech of my right hon. Friend the Member for Leeds, East (Mr. Healey), but no one hearing both speeches could imagine that he has succeeded. The Secretary of State has not applied his mind to any of the immediate points that my right hon. Friend put to him. He has not attempted to explain why the understanding with the American Government about how British participation is to take place should remain secret. Nor has he explained why so many infringements have been permitted of the original terms agreed between the Prime Minister and the United States President. To the extent that he has sought to do so, it has been by repudiating the words of the United States President, who has said on a number of occasions, as have many of his supporters, that he intends to go ahead with the programme in any event.

If the claims for the strategic defence initiative programme were fundamentally correct, there would be a case for that claim, but the British Government clearly do not accept that. It seems that they still retain some fondness for the Foreign Secretary's criticisms of the original proposal. In this context, it would have been proper for the Foreign Secretary himself to reply to the debate, just as the Government should properly have provided the time for this debate and for the Foreign Secretary to deal with the profound issues that he has emphasised. If the Foreign Secretary's criticism—it is no use trying to pretend that it was not criticism—of, for example, the impossibility of making a distinction between research and development because if the research went ahead the pressure for development would become overwhelming was a substantial criticism, it remains so today.

The Government have not made the slightest effort to discuss in the House or in the country the serious arguments made not just by the Opposition but by the Foreign Secretary himself. That speech by the Foreign Secretary was widely regarded as a most valuable contribution to the debate. I wonder whether that debate was transferred to the Cabinet or whether it followed the course so frequently adopted by the present Administration whereby major issues which should be debated in Cabinet are hurried through, hushed up or pushed into secret agreements so that debate in Cabinet and in the House is prevented.

The whole way in which the Government have dealt with these matters exposes their failure to discuss the issues in the country. At times, the Secretary of State for Defence talks as though the strategic defence initiative is just a minor logical development of what has gone before, but everyone knows that it is something quite different. The American President and Defence Secretary have presented it as something quite different. That being so, the whole matter should have been debated in the House. The only contribution that the Secretary of State for Defence has made will be to ensure that the discussion will proceed on very many future occasions.

The Secretary of State for Defence talks about reality and the way in which the Opposition approach these matters. I wish to make only a short speech, but I should like to quote at some length the comments that have been made about this, brought up to date not by the Opposition —although they vindicate all that my right hon. Friend the Member for Leeds, East has said — but by Lord Zuckerman, chief scientific adviser to the British Government for several years and a man whose integrity, intelligence and copious knowledge of these matters no one has ever dared to question. He probably knows more about combined military, defence and scientific implications than anyone else on the face of the planet. He has always tried to give his views as clearly and openly as he as he can. He describes the reality of which the right hon. Gentleman spoke somewhat differently.

Lord Zuckerman has described how many of these matters featured in the debates that took place before the signature of the ABM treaty in 1972. One reason why Professor Zuckerman is so worried is that what is happening will destroy that treaty. Very few treaties prevent the world from going ahead full speed in the nuclear arms race. He is worried that the ABM treaty will be destroyed just as some of those treaties, such as the nonproliferation treaty or the comprehensive test ban treaty, are also in jeopardy. The American Government are injuring and tearing up the ABM treaty, and the British Government are helping them. All the right hon. Gentleman's pious words about his desire to sustain that treaty are disproved by the reality of what has happened.

What happened in 1972? They had a discussion about defensive systems. That is why they came to the ABM treaty and why it was so important. That process is described by Professor Zuckerman in a recent article. He wrote: The result was the ABM Treaty of 1972, a treaty that limited ABM deployment to two sites only—later changed to one—in each country. The treaty did not bar development work that improved the radars, computers, and defensive missiles deployed within the two sites, but specifically prohibited the development of any type of space-based ABM system. Stability was then the order of the political day. It is that stability that is now being threatened and broken by the course recommended by the American Administration, which, tragically, is approved of by the British Government.

Professor Zuckerman examined the arguments. The main argument that has been put today, and which is incorporated in the Government amendment, is that the Russians have been doing it anyhow, so we should do it. If that were true in the precise terms in which they say it, it would be a very powerful argument. I have not the slightest doubt that the Government will rely on it to the maximum. That is why Professor Zuckerman, who knows a good deal more about these issues than the Government, has dealt with the matter. He says: One major justification continues to be heard: that the Russians are engaged on work that corresponds to different elements of the SDI program, and that in many ways they are ahead of the United States. We have also been told that some Russian actions have already breached the terms of the 1972 ABM Treaty. Specific violations are spelled out in impressive brochures.The Russians counter by pointing to American actions which in their view are breaches of the treaty. They have even offered to suspend work on the much spoken of, and highly vulnerable, vast phased-array radar system which they are building at Krasnoyarsk if the United States abandons its program to modernize the radar complexes which it has at Fylingdales in the United Kingdom and Thule in Greenland. Their spokesman argue that these modernization plans, and particularly the rebuilding of Fylingdales as what is rumored to be a 360 degree phased-array radar complex, is far more questionable than what the USSR is doing at Krasnoyarsk. This is Professor Zuckerman examining the facts—the realities to which the right hon. Gentleman referred. He continues: A further accusation by the administration is that the USSR has committed a far greater investment of plant space, capital, and manpower to advanced BMD technologies than the US has. This extravagant claim is not borne out by a CIA document about Soviet efforts which was presented to the Armed Services Committee of the Senate on June 26, 1985. Indeed, the document expresses doubt about the applicability of even a network of Krasnoyarsk systems— regarded as the most serious breach of the 1972 treaty — for widespread ABM deployment. Dr. Garwin, in a follow-up to testimony presented to a congressional study group on October 10, 1985, has also pointed out that the better part of the large Soviet program on strategic defense is devoted to the upgrading of its anti-aircraft defense system. This is not a judgment given by a partial mind. It is given by Professor Zuckerman, and is concerned with developments that have already taken place. Of course he is horrified at the possibility that we shall see destroyed one of the very few treaties that works — the ABM treaty. The right hon. Gentleman said that he wants to preserve it. Professor Zuckerman continues: It was therefore unfortunate that immediately before the Geneva summit, Robert McFarlane, then the head of the National Security Council, declared that no aspect of the development of space-based BMD components is prohibited by the 1972 ABM Treaty, and that what was intended about testing and development merely implied a shift from the technology that was available at the beginning of the 1970s to what can be undertaken today. What Professor Zuckerman underlines most of all in his article—indeed, it is the conclusion of his article—is that it is absurd, it is highly dangerous, for Britain, the United States and other Western countries to weaken the 1972 agreement, and to make it capable of more flexible interpretation. The amendment puts exactly such an interpretation on the treaty. Professor Zuckerman accuses the American Administration of weakening enormously the way in which the ABM treaty is applied and can be applied. If the SDI programme goes ahead, the ABM treaty will be torn up altogether.

This is the situation at which we have arrived. Professor Zuckerman concludes his article with some very serious words. There have not been so many treaties that guard against the pace of the nuclear arms race. There have not been so many treaties that have actually worked, but there have been a few and some of them are now threatened. Unless the British Government wake up and do something at the last moment, the comprehensive test ban treaty may go. The non-proliferation treaty is also threatened. The British Government do not appear to have done anything about that. The ABM treaty is now threatened, and the right hon. Gentleman's words will not do anything to protect that treaty, particularly if they conflict with the deeds — and the deeds are the signatures which the British Government put to the secret agreement with the United States. Why did they want the British Government to come along and sign on the dotted line? That has been used by the American Administration to support not only the first next step along the road, but the whole programme that they are seeking to carry through, which would involve the destruction of one of the very few treaties that guard against the renewal of the race in the most intemperate and dangerous manner.