Putin saw the Ukrainian revolution as a challenge to him personally, and I think that's why he, in fact, over-reacted. I think his occupation of Crimea and then annexation for him was actually a mistake from Russia's point of view. And then his invasion of Eastern Ukraine was also a mistake. He imagined that he would invade Eastern Ukraine and then eventually split the country in half, and he discovered that in fact, Russian-speaking Ukrainians are not Russians, and they didn't support him.

The world has always been a dangerous place. Now it is dangerous in a different way, because the world order that we've known since the end of the Cold War has been radically transformed. All of the institutions that preserved peace and promoted global trade will be weaker - NATO, the EU, NAFTA - and US relationships with other countries will change, too.

Putin imagined it would be different. So, like many Russian leaders before him, he imagined that Ukraine was basically Russia, but they speak with a funny accent. Actually, it's not Russia; it has a different identity. It has a very different language. Russians don't automatically understand Ukrainian. And, in particular, the way Ukraine has developed over the last two decades is different from the way Russia has developed.

Putin saw the Ukrainian revolution as a challenge to him personally, and I think that's why he, in fact, over-reacted. I think his occupation of Crimea and then annexation for him was actually a mistake from Russia's point of view. And then his invasion of Eastern Ukraine was also a mistake. He imagined that he would invade Eastern Ukraine and then eventually split the country in half, and he discovered that in fact, Russian-speaking Ukrainians are not Russians, and they didn't support him.

Putin discovered that when he invaded Ukraine, he expected the Ukrainians to rise up and join him and say, "Yes, we want to be part of Russia," and that didn't happen. And they've been paying, actually, I think quite a high price for it, both in the ongoing war in Ukraine - which is I think increasingly unpopular in Russia - and also in the Western sanctions, and in general, the separation from the West that was caused by that.

Steve Bannon, the White House chief strategist, appears to imagine an alliance between Trump, Le Pen, Geert Wilders and Nigel Farage. Call it the populist international, a fraternal association of the nationalist right, binding people who want borders, across borders.

Unlike most European countries, the police in the US are decentralized; even the FBI has regional offices. Amending the constitution is a long and tedious process.