Is there any possibility of giving international air travel, which we all need and use and hate, a touch of glamour, or even of reliable, soulless efficiency? I suspect future historians will puzzle over our failure. But by then, of course, we shall be in the age of mass space travel, with its fresh and unimaginable crop of horrors.

Indeed it is the protean ability of Western civilization to be self-critical and self-correcting - not only in producing wealth but over the whole range of human activities - that constitutes its most decisive superiority over any of its rivals.

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.

The planet Earth, though not threatened with destruction by man-made global warming, is by no means indestructible. There are many unpredictable events within our solar system, and still more outside it, that could make Earth uninhabitable by humans.

It's like how science fiction in the '50s was a way of talking about war without actually having to risk any political capital. The obvious metaphor is power and powerlessness, but I also think it's a way of experimenting with dangerous feelings in a safe arena and trying things out.

I would say that the Pentagon Papers case of 1971 - in which the government tried to block the The New York Times and The Washington Post that they obtained from a secret study of how we got involved in the war in Vietnam - that is probably the most important case.

The first thing I see is the obligation to serve peace.

We want peace and development in all 10 states of South Sudan - we don't want military backing.