Putin has calculated that he can ride out whatever sanctions the west can throw at him. There are already splits: we can't agree that we should exclude Russia from the SWIFT international banking system (used to pay him for Russian oil and gas, for example). A couple of weeks ago he was cosying up to the equally nasty charlatan President Xi. You can bet your life that there will be plenty of sanctions mitigations coming from that quarter, and Xi will be watching with interest to see if there's a template here for taking Taiwan. This next bit might seem trivial, but Russia is a football-mad country which has now had the prestigious Champions League (aka European Cup, as was) final taken away. Russia still has teams in European competitions as well as an interest in the forthcoming World Cup. Take all that away (which I think should be done), and there are going to be tens of millions of very angry Russians, and it won't be us who they blame. I think that Russian public opinion turning against Putin is almost the only hope of drawing his sting. He's a nasty piece of work and will use brutal methods to suppress dissent, but, unlike in the bad old Cold War days, he won't be able to hide what he does from the world behind a wall of secrecy.