Right now, there are 100,000 Russian soldiers on the border of Ukraine. Desperate Ukrainian civilians are training as volunteers to defend their country. This is Europe's next war zone.

NATO countries are divided over their response. Many think that Russia is bluffing. They argue it does not want to go to war with the USA, which is extremely powerful. 

But others are less sure. The Russian army might not be as big as America's. But it is modern and it will be fighting on territory it knows. 

Western powers want to avoid war. They are searching for a diplomatic solution. But to get that, they need to work out what Vladimir Putin wants.

Putin is unlike most Western leaders. He has built up a reputation as a scrappy street fighter. But he is also a ruthless thinker. He is an expert in judo and Sambo. Both are martial arts that teach their students to watch for an opponent's weaknesses. Putin has often used these skills against Russia's international rivals.

Very few Western leaders truly understand what motivates Putin, and so they are frequently taken by surprise. 

But one big danger of Putin is that he does not understand Western leaders. When he does not know something, he fills the gaps with plots and conspiracies.

America's foreign policy is about spreading democracy around the world. It is not supposed to be a threat to Russia.

But Putin sees it as a plot. So when Russia's neighbours embrace democracy and ask to join NATO, he responds aggressively. 

Yes: Putin is not a foolish thug. He is a thoughtful man with a keen strategic mind. He has worked with the West before and knows its weaknesses. We should not write him off.

No: We know all we need to know about Putin. When he feels threatened, he resorts to violence. He does not care that an invasion of Ukraine would cost thousands of lives. The only tactics he knows are bullying and brinkmanship. Understanding his traits will help us control the situation.

Or... We should use our understanding of Putin to come to a peaceful conclusion. We know that he might lash out when threatened. But we also know that as a strategic man, he will understand the risks in starting a war and taking on huge world powers. This is the key to a solution.