A capitalist economy hums when leading businessmen are bubbling with animal spirits and are prepared to sink their money into risky ventures.

In the past, the U.S. has shown its capacity to reinvent its gifts for leadership. During the 1970s, in the aftermath of the Nixon abdication and the Ford and Carter presidencies, the whole nation peered into the abyss, was horrified by what it saw and elected Ronald Reagan as president, which began a national resurgence.

In the long term, it is desirable that the human race, faced with the prospect of extinction on Earth, should prepare an escape route for itself to another inhabitable planet.

I don't write huge books any more. I used to write 1,000 printed pages, but now I write short books. I did one on Napoleon, 50,000 words - enjoyed doing that. He was a baddie. I did one on Churchill, which was a bestseller in New York, I'm glad to say. 50,000 words. He was a goodie.

Marxism, Freudianism, global warming. These are proof - of which history offers so many examples - that people can be suckers on a grand scale. To their fanatical followers they are a substitute for religion. Global warming, in particular, is a creed, a faith, a dogma that has little to do with science.

If the decline of Christianity created the modern political zealot - and his crimes - so the evaporation of religious faith among the educated left a vacuum in the minds of Western intellectuals easily filled by secular superstition. There is no other explanation for the credulity with which scientists, accustomed to evaluating evidence, and writers, whose whole function was to study and criticize society, accepted the crudest Stalinist propaganda at its face value. They needed to believe; they wanted to be duped.

To many, Heathrow in August is a paradigm of Hell.