The absence of a focal enemy, which is what the Cold War had provided; the complexity of the developments that are occurring that mean that the world is just extremely complicated - lots of different and competing stories and strands; the continuing reality of megaterrorism; and the dysfunctionality of our politics that has neglected the foundations of the U.S. role in the world; have altogether left us somewhat confused.

And I hope that we can learn the lessons of the past in looking at the current challenge that China poses to a ruling America.

For interests that are vital to the U.S. - that is, essential for our survival and wellbeing - the U.S. should be prepared to use military force - including unilaterally, if necessary.

I think the election of Trump was an expression of what happens in ruling powers as they become alarmed.

I think we should be organized in something called an Alliance Against Nuclear Terrorism. In the same way that NATO was the great alliance of the Cold War and served a great purpose then, we need now, in the war on terrorism, a new alliance, the mission of which would be to minimize the risk of nuclear terrorist attacks, and the members would agree to sign on to the gold standard.

One of the three big factors that count against war in the relationship between China and the U.S. are, first, nuclear weapons and even a condition of mutual assured destruction. Secondly, one's got two economies that have become so deeply interlaced that a war between the U.S. and China would leave Wal-Marts empty and Chinese factories producing for nothing. Thirdly, climate - if between the two of us, we keep doing what we're doing, we can create a climate in which our grandchildren won't be able to live.

Given that the Al Qaeda core has been significantly destroyed or disabled, and that the leadership seems to be essentially on the run or in hiding, it would lead me to think that probably it is one of the less centralized groups that might be the greatest danger.