“The Prime Minister constantly asserts that the nuclear weapon has kept the peace in Europe for the last 40 years… Let us go back to the middle 1950s or to the end of the 1940s, and let us suppose that nuclear power had never been invented… I assert that in those circumstances there would still not have been a Russian invasion of western Europe. What has prevented that from happening was not the nuclear hypothesis… but the fact that the Soviet Union knew the consequences of such a move, consequences which would have followed whether or not there were 300,000 American troops stationed in Europe. The Soviet Union knew that such an action on its part would have led to a third world war—a long war, bitterly fought, a war which in the end the Soviet Union would have been likely to lose on the same basis and in the same way as the corresponding war was lost by Napoleon, by the Emperor Wilhelm and by Adolf Hitler…
For of course a logically irresistible conclusion followed from the creed that our safety depended upon the nuclear capability of the United States and its willingness to commit that capability in certain events. If that was so—and we assured ourselves for 40 years that it was—the guiding principle of the foreign policy of the United Kingdom had to be that, in no circumstances, must it depart from the basic insights of the United States and that any demand placed in the name of defence upon the United Kingdom by the United States was a demand that could not be resisted. Such was the rigorous logic of the nuclear deterrent…
It was in obedience to it… that the Prime Minister said, in the context of the use of American bases in Britain to launch an aggressive attack on Libya, that it was "inconceivable" that we could have refused a demand placed upon this country by the United States. The Prime Minister supplied the reason why: she said it was because we depend for our liberty and freedom upon the United States. Once let the nuclear hypothesis be questioned or destroyed, once allow it to break down, and from that moment the American imperative in this country's policies disappears with it.
A few days ago I was reminded, when reading a new biography of Richard Cobden, that he once addressed a terrible sentence of four words to this House of Commons. He said to hon. Members: "You have been Englishmen." The strength of those words lies in the perfect tense, with the implication that they were so no longer but had within themselves the power to be so again. I believe that we now have the opportunity, with the dissolution of the nightmare of the nuclear theory, for this country once again to have a defence policy that accords with the needs of this country as an island nation, and to have a foreign policy which rests upon a true, undistorted view of the outside world. Above all, we have the opportunity to have a foreign policy that is not dictated from outside to this country, but willed by its people. That day is coming. It may be delayed, but it will come.”

Speech on Foreign Affairs in the House of Commons http://hansard.millbanksystems.com/commons/1987/apr/07/foreign-affairs (7 April 1987).
1980s