The danger of the war spreading into Europe has been clear from the start of the problems with Russia over Ukraine back in 2014, when Putin occupied Crimea. Since then Western countries have been doing everything they can to avoid it .
Successful negiotiations are dependent on both sides being prepared to negotiate. Does anyone think Putin is willing to negotiate?
Putin was hoping NATO would close the air space over Ukraine and monitor it with aircraft from their air forces. Either a Russian aircraft would be shot down, or Putin would say one had, with photos etc to prove it. He would then declare outright war on NATO. He would use nuclear war heads and Britain would be one of the main targets, together with Germany, France and the USA. Do not forget how close North America is to Siberia.
I think as that is not working, his next ploy will be to use battle field nuclear arms or thermobarric artillery in Ukraine. He has already used cluster bombs. All these contravene the Geneva Convention and other rules of war and an official enquiry into his war crimes has already started.
In Russian terms, Putin is an old man. Average life expectancy of a male baby born in Russia today is 68 years. Putin is 69. Healthy life expectancy is 58
Putin is obsessed by his place in history. So far it is as the leader of a declining country; economically stagnant, less and less important in world affairs and completely over taken by China.
He knows the time he has left him to make a mark in history, is limited. His focus now is now on rebuilding Russia as it was in its heighday, when the Ukraine was in integral part of 'Mother Russia'. He is a rat caught in a trap, he has nothing to lose, and knows no moral limits to what he can do to get his own way.
So, Bea65Putins war will spread to Europe and beyond. The only people who can stop it are the people around him.