Nationalism has nothing to do with the rule of law, justice, or opportunity.

From my point of view, the Dreyfus affair is most interesting because it was sparked by a single cause celebre. Just one court case - one disputed trial - plunged an entire country into an angry debate, creating unresolvable divisions between people who had previously not known that they disagreed with one another.

Democracy in some ways is a very illogical political system. When you win an election, you have to preserve the institutions that would make it possible for your political enemies to win next time. If you think about it, that's almost antithetical to human nature.

One of the reasons why many British voters chose to leave the European Union was because they distrusted European institutions. Of all the many costs of Brexit, this was one I did not foresee: That it could wind up damaging the nation's faith in its own institutions too.

All over the world, the Trump administration is pursuing a range of policies: tweeting insults at Maduro, negotiating with a defiant North Korea, sending a small fleet of warships to the Persian Gulf to intimidate Iran. But the speed with which the president always sours on these efforts means they can never be part of any discernible strategy.

Given the right conditions, any society can turn against democracy. Indeed, if history is anything to go by, all societies eventually will.

We don't live in a culture of censorship, such as the Soviet Union's; we live in a culture where there is too much information, where words are drowned out, not banned, and important ideas and events are ignored.

What links Donald Trump, Viktor Orban, Andrej Babis, Jaroslaw Kaczynski and Marine Le Pen is one simple character trait: hypocrisy. These politicians aren't tribunes of the people, they are hucksters. They aren't bitter enemies of the Western system; they are con artists who seek to profit from it.

Everywhere he goes, Trump is bored by working meetings and rude to those who attend them. He can't make deals or negotiate because he doesn't know enough about the issues.

We now expect Google, Facebook, Twitter and other companies to police the Internet for dangerous and illegal material - violent, terrorist, criminal - and some democratic governments require them to do so. But what if they did decide to repress material for political reasons? How would we know?