It also destroyed careers. It may destroy more. It certainly changed them. Harold Macmillan never fully recovered from Charles de Gaulle's first veto on British membership. Margaret Thatcher was brought down by Europe. If she had not taken the line she did and said "No. No. No." in the House in October 1990, Geoffrey Howe would not have made the speech he did, and Michael Heseltine would not have stood against her in the first ballot.
Roy Jenkins's career was not exactly destroyed by Europe. There he sits in the upper House, recipient of the OM and much else besides, the grandest old man in politics since... well, I suppose since A J Balfour. Still, he might have succeeded Harold Wilson had Europe not intervened.
In the early 1970s Mr Tony Benn came up with a wheeze for a referendum on our membership of the market, which we were to join in January 1973. In constitutional matters, Mr Benn is certainly the most influential of our post-war politicians, rivalled in this respect only by the late Humphry Berkeley.
In his original incarnation as Wedgbenn of Mintech, he had been all for Europe, on the plausible ground - which has lost none of its persuasiveness with the passing of the years - that only an economy of European dimensions could effectively control the multinational corporations. By 1971 he had moved to the left, opposition to Europe being in those days necessary for membership of that grouping.
He was joined in his campaign for a referendum by Richard Crossman, then editor of the New Statesman. Crossman's motives were perhaps less pure than Mr Benn's. He certainly wanted to force Lord Jenkins, who was the deputy leader, out of the party. In the long term he succeeded. One is tempted to conclude that it was the solitary success of Dick's entire political career.
In 1972 Lord Jenkins resigned the deputy leadership over the adoption of the referendum as party policy; in 1976 he left Westminster for Brussels when James Callaghan, the new prime minister, refused to make him foreign secretary; in 1979 he delivered the Dimbleby lecture; and in 1981 he formed the SDP. It is possible that if Lord Jenkins had not relinquished the deputy leadership, he would have won - anyway done better in - the leadership election in 1976 instead of coming a bad third. Even so, he has denied having any regrets about resigning. The referendum duly took place in 1975, perhaps the last major event over which Wilson was to preside. By an unexpectedly large majority, our membership was confirmed.
Mr Tony Blair is behaving over the euro much as Wilson did over Europe. In 1974-75, for instance, there was an enormous song and dance about renegotiating terms. The revised terms were declared satisfactory - more, a Herculean feat of diplomatic skill - as everyone knew they would be. Compare what happened then with Mr Blair's terms, as set out last week. I quote what the man said rather than what other people say he meant:
"Sustainable convergence be- tween the UK and countries within the euro zone; flexibility to adapt to change in the UK and in continental Europe; the impact on investment and the UK financial services industry; and whether joining the single currency would be good for employment."
Mr Blair claimed he was merely echoing what Mr Gordon Brown had said in the House in October 1997. Though I have not verified Mr Brown's precise words on that occasion, I am sure Mr Blair was telling the truth. That, however, is not the immediate point. The conditions are like a tank painted a forbidding shade of khaki which, on closer inspection, turns out to be made entirely of cardboard, string and sticky tape and is, on that account, liable to come to pieces when faced with a little light rain.
In other words, the criteria are satisfied if Mr Blair and Mr Brown say they are satisfied. Virtually the sole objective tests are the comparative rates of interest and levels of employment in the UK and in those countries which have adopted the euro. At present ours are both relatively high. We would presumably be prepared to lower our rate of interest if the European countries raised their level of employment. Mr Blair did not say anything so simple as that. We may well find ourselves having to tolerate increased unemployment to bring it up to a satisfactory European level. Who can tell? Who indeed!
But in another respect Mr Blair was more forthcoming than any leader has ever been. For this he deserves some credit. He was certainly franker than Mr Brown, who said that adopting the euro had no "constitutional" implications. Fifteen months on, Mr Blair could say: "I do not dismiss the constitutional or political issues. They are real. Monetary union is a big step of integration, but so were the Single European Act and the European Union itself... It is, of course, an intensely political act. However, just as the euro cannot be conceived of except politically, it cannot be made to work except economically."
The reference to the Single European Act was presumably an attempt to embarrass Mr William Hague. It is always being said that it was Lady Thatcher who "signed" this measure. Why anyone should think it is part of a prime minister's constitutional duties to sign statutes I do not know. They begin:
"Be it enacted by the Queen's most Excellent Majesty, by and with the advice of the Lords Spiritual and Temporal, and Commons, in this present Parliament assembled, and by the authority of the same..."
The prime minister does not come into it. Still, I know what people mean: that this most integrationist of measures was passed under a Thatcher government. She says now that no one explained to her what it meant at the time, which is not an excuse that would stand up in a court of law.
But our politicians have always been coy about Europe. One of the most reticent was Sir Edward Heath. In the 1970 election his party declared that its sole commitment was to negotiate, "no more and no less". Three years later we were in Europe. Two years after that we were cemented in. Mr Blair has at any rate been franker than any of his predecessors. He has even provided a timetable: "The whole process - from a positive referendum result to the withdrawal of sterling - could be completed in about three years."
Lord Dahrendorf has pointed out that what no modern government can afford to do is lose a referendum. If Mr Blair had possessed the nerve to hold one on the euro in summer 1997, he would probably have won; rather as he did in the autumn on Welsh devolution. The fiddling around with cash registers, computers and the like which he is now demanding (and to which the Government is making no substantial contribution) is manifestly an attempt to present the citizens with a fait accompli in 2001. Or, as the Queen says in Alice in Wonderland: "Sentence first - verdict afterwards."