Putin and the rest of the world know that the new Ukrainian government has until the first hard snow to get control of the situation. Despite what the western media claims, about half of the Ukraine (mostly in the small towns and countryside) and almost all of the Crimea are pro-Russia. When the weather gets cold and cheap Russian natural gas isn't available, support for this new government is going to dry up quickly.
Although admittedly the former Ukrainian government was a puppet of Moscow, they at least kept the trains running on time. When the majority of the population starts shivering and can't get a decent meal, this entire "let's turn Ukraine into modern Europe movement" will fade like a distant memory.
The Europeans love cheap Russian gas way too much to do anything significant other than to protest a little and perhaps impose some token sanctions, they also don't want the return of the bad old days of the cold war, and the" spy vs spy" insurrection game. Europe has become a powder keg of multiple cultures and all it would take would be a few whispers here, a little money there, to start plenty of problems at home.
The UN is powerless because Russia and China are both permanent members of the UN Security council, and can veto any UN proposal, and China has been consistent in vetoing just about every proposal. Russia and China are also beginning to warm to one another, despite US attempts to keep them divided.
So that leaves the US which is hamstrung ten ways to Sunday with our own sluggish economy, getting out of two wars, and a leader that appears to get his daily briefing from CNN instead of the CIA.
I think it's fair to say that regardless of the outrage, Putin has been playing chess while the US and the rest of the world has been playing marbles. It might not be "checkmate" geopolitically, but it's pretty close. Time is swiftly running out for the Ukraine and Putin controls the clock.