In the midst of what is agreed to be an important and serious debate, I was astonished to hear the overblown language of the right hon. Member for Llanelli (Mr. Davies). It is clear that on the Opposition Front Bench we have not one, but two Welsh windbags.

The right hon. Member for Blaenau Gwent (Mr. Foot) asked about the absence of my right hon. and learned Friend the Secretary of State for Foreign and Commonwealth Affairs. I know that he would have liked to take part in this important debate, but he is accompanying Her Majesty the Queen on her state visit to Nepal, and that date was in his diary long before the Labour party decided to have this SDI debate.

The right hon. Member for Leeds, East (Mr. Healey) implied that three of the four Camp David points agreed in December 1984 between President Reagan and the Prime Minister, which remain the basis of the Government's policy and which have recently been reaffirmed by the State Department, have already been broken. That is not so. The United States research programme and our participation in it is at the heart of the debate. The first Camp David point, which the State Department subsequently reaffirmed, is that the United States and Western aim is not to achieve superiority, but to maintain the balance, taking account of Soviet developments. It underlines the need to continue the research effort in the West in order to match and to hedge against the well-established Soviet programme.

The Soviet programme is long-standing and extensive. There has been research by the United States over the same period, but it is a simple fact, which the House will recognise, that scientists will continue to investigate new technologies. The human mind cannot be prevented from thinking, inventing, exploring and expanding the potential of the future. Perhaps this potential will never be realised, or perhaps it will be fully implemented to the greater good of the international community, but in any case the process will continue. Surely, in a democratic system like ours, our people and our researchers and scientists cannot be prevented from being involved.