One lesson is to not to play desperately if your position is worse but still reasonable. Lashing out wildly in an inferior position usually only hastens defeat. Meanwhile, solid, stubborn defense can demoralize the attacker, make him lose confidence. When that happens, the tables can turn. Keep fighting, stay steady, keep morale high - and public protests are good for all of these things.

The most hopeful approach to peace in Ukraine is the Minsk Agreement, which includes Moscow.

Many so-called pragmatists want nothing to do with space exploration or other kinds of ambitious endeavours that don't have a clear payoff. This mentality is hugely damaging to our success as a civilization. Our desire to understand the universe is kindled by curiosity and wonder, and this has fuelled countless scientific breakthroughs.

The West can't come up with anything to deal with Moscow, except appeasement.

I now have Croatian citizenship, but I only accepted it because Croatia allowed me to keep my Russian passport.

Dictators are not strategists in the way I normally use that term. All the dictator cares about is survival. That means constantly worrying about the tactical response, "What do I do today, tonight, tomorrow morning, to stay alive?" Vladimir Putin doesn't care what happens a year or five years from now. He just cares about staying in the game. That is all he needs to survive.

We see threats to liberal democracy coming from lots of directions. We have to create something new, a common response, because in so many places - the UK, France, Germany - ultranationalists and the far left threaten the free market and liberal democracy.