What has come to be called the balance of terror may seem less frightful to fanatics leading a country with a population of 600 millions. Even a war directed explicitly against centers of population may seem to it tolerable and perhaps the best means of dominating the world. Chou En-lai is reported to have told a Yugoslav diplomat that an all-out nuclear war would leave 10 million Americans, 20 million Russians, and 350 million Chinese.

The Nixon Administration had systematically sought to change the context of the Cold War. This was not because we had become blind to Soviet ideology; rather we had concluded that the Soviets' ideological reach was collapsing. In two generations of Communist history, no Communist Party had ever won a free election. The only allies of the Soviet Union were in Eastern Europe, and they were being held in line by what amounted to Soviet military occupation. Once our opening to China was completed, the Soviet Union faced a coalition of all the industrial nations in the world in tacit alliance with the most populous nation. Sooner or later this equation would work in favor of the democracies, provided they could contain Soviet adventures by deterrence and give the Soviets a chance to reduce confrontation by opportunities for cooperation.

As the impeachment proceedings gathered momentum, Nixon's personal conduct began to mirror his political decline. He kept fully abreast of the various foreign policy issues and at no point failed to make the key decisions. But, as time went on, Watergate absorbed more and more of Nixon's intellectual and emotional capital. As day-to-day business became trivialized by the increasingly apparent inevitability of his downfall, I felt enormous sympathy for this tormented man whose suffering was compounded by his knowledge that his tragedy was largely self-inflicted. Yet by early July 1974, I, like the other few survivors of Nixon's entourage, was so drained by the emotional roller coaster that I was half hoping for some merciful end to it all.

I was intellectually convinced that Hanoi would settle only if deprived of all hope of victory by a determined military strategy. But I was emotionally close to many of the more moderate of the protesters who had been my contemporaries at university; therefore I was also the principal advocate in the administration for negotiations for a political solution to give the people of Indochina a genuine opportunity to choose this future. It turned out to be a rough ride, rougher by far than I imagined when I started on the task. Since then, the categories of our national debate on Vietnam have remained largely unchanged, compounded with the passage of time by an amnesia that suppresses events but remembers encrusted hatreds. A balanced judgment on Vietnam continues to elude us - and therefore the ability to draw lessons from a national tragedy which America inflicted on itself.

Where eminence must be reached by endless struggle, leaders may collapse at the top, drained of creativity, or they may be inclined to use in high office the methods by which they reached it. When political leaders are characterized primarily by their quest for power, when they decide to seek office first and search for issues later, then their technique to maintain power is necessarily short-range and manipulative.

I think of myself as a historian more than as a statesman. As a historian, you have to be conscious of the fact that every civilization that has ever existed has ultimately collapsed. History is a tale of efforts that failed, of aspirations that weren't realized, of wishes that were fulfilled and then turned out to be different from what one expected. So, as a historian, one has to live with a sense of the inevitability of tragedy. As a statesman, one has to act on the assumption that problems must be solved.

For 400 years, world history was made by Europeans. Many of the great ideas by which we live — constitutional government, freedom of the individual, the ideas of the Enlightenment — originated in Europe and were spread by Europe around the world. Now this region, which was dynamic and built the world, has become too preoccupied with itself. It confines itself basically to the exercise of soft power. At present, no European government has the capacity to ask its people for sacrifices on behalf of foreign policy. Unless Europe can recover some of its historic dynamism, there will be a big hole in the world system as it has until now manifested itself.

Nelson Rockefeller, I am certain, would have made a great President. He possessed in abundance the qualities of courage and vision that are the touchstones of leadership. But at the moments when his goal might have been realized, in 1960 and again in 1968, he uncharacteristically hesitated. In the service of his beliefs he could be cold-blooded and ruthless; he was incredibly persistent. Yet there was in him a profound ambivalence.

The domestic divisions that grew out of Vietnam were generally treated in the public discourse as a clash between those who were "for" the war and those who were "against" it. That, however, was not the fundamental issue. Every administration in office during the Vietnam war sought to end it - nearly desperately. The daunting and heartrending question was how to define this goal.