The Houthi have local religious grievances, being Shiites in a majority Sunni land. But they are also agents of Shiite Iran, which arms, trains, and advises them. Their slogan - 'God is great. Death to America. Death to Israel' - could have been written in Persian.

Americans are not intrinsically imperial, but we ended up dominant by default: Europe disappeared after the Second World War, the Soviet Union disappeared in 1991, so here we are.

There are cycles in American politics. US cycles are even more pronounced because we Americans have a totally entrepreneurial presidential system. We don't have parliamentary opposition parties with a shadow prime minister and shadow cabinets. Every four years, the opposition reinvents itself.

The only reason the president insists on raising [tax] rates is because he knows it will destroy Republican unity, it will cause a complete fracture of the Republican majority in the house, it will hand him a Congress that he can then manipulate for the next two years at least because the Republicans will be neutered. ... This is entirely a political action, a way to get a surrender from the Republicans.

I happen to believe that the preemption school is correct, that the risks of allowing Saddam Hussein to acquire his weapons will only grow with time.

Where there is a confluence of interests among nations, as, for example the swine flu or polio, you can get well functioning international institutions like the World Health Organization. And you can act. Climate change is different, because the science remains hypothetical and the potential costs staggering.

If we insist that public life be reserved for those whose personal history is pristine, we are not going to get paragons of virtue running our affairs. We will get the very rich, who contract out the messy things in life the very dull, who have nothing to hide and nothing to show and the very devious, expert at covering their tracks and ambitious enough to risk their discovery.