You really struggle to be a successful empire if you are also the world's biggest debtor.

All empires have depended on local legitimacy and local collaboration; they are not based primarily on coercion. An imperial rule that relies wholly on coercion can't endure. It's too expensive.

I would say I'm a 19th-century liberal, possibly even an 18th-century one.

Empires, essentially, create order. In their absence, you don't end up with lots of happy, little nation-states full of people sitting around campfires singing John Lennon's "Imagine." What you end up with is civil war, anarchy.

In the old days it would have been a relatively simple matter to have checked Hitler's territorial ambitions. All you'd have needed would have been the 1914 combination of Britain, France and Russia. Indeed, if such an alliance had acted decisively to defend Czechoslovakia in 1938, Hitler might even have been overthrown by his own military. But it was not to be.

If the financial system has a defect, it is that it reflects and magnifies what we human beings are like. Money amplifies our tendency to overreact, to swing from exuberance when things are going well to deep depression when they go wrong. Booms and busts are products, at root, of our emotional volatility.

The Japanese Co-Prosperity Zone began as a racist utopia and ended as a cross between an abbatoir, a plantation and a brothel.