Putin has been running rings around the so called leaders of the west for years.
He also makes no secret of longing for the old days of the USSR and the security its satellite states gave to the motherland.
A quick look at Ukraine
Whether Yanakovich is a dodgy character or not is irrelevant.
He was democratically elected into power by the people of the Ukraine and was removed by mob rule which is always going to end in tears. See Libya and Syria for details.
The western half who mostly speak Ukrainian wants to be in the EU / NATO and all the grants / benefits it brings.
The eastern half who mostly speak Russian wants to renew closer ties to Russia.
Russia is genuinely paranoid about having a NATO country sat on its doorstep too.
Where will it end ?
Imo, this is the start of Cold War 2

Ukraine will end up being split in two with a big fence between them.
What can the west do about it ?
Sweet F**k All

As said, Russia holds most of the cards again.
They have oil, gas and raw materials a plenty.
Us in Europe have next to nothing and have to go cap in hand to Putin to supply the gas or mainland Europe will freeze

Us in the UK at least had the brains to do a deal with Norway and build a pipeline across the North Sea.
We also have been increasing the amount of bulk LPG we import via tankers so we should be okay on that front

There is no way on earth that the UK will back sanctions against Russia because the first thing they would do is take there money out of the London banking world. This would screw us up big style

What can NATO do about it ?
Eh, nothing

The hierarchy couldn't organise a piss up and a brewery and we haven't the men, machines, ammo or spares to go against Russia like we could have done 25 years ago

In fact the only way we could hold Russia if it got nasty is by using Trident and that is basically the end of the world

If this happens, the question for me is .............. who's next ?
Poland or maybe Estonia ?
I just hope Rods family are in the western side of the country

One last thing about Russia.
Where as we in the west always tend to think short term to keep the votes / people happy, the Russians and Chinese always play the long game

If the western leaders has any brains at all, the above fact should scare the shit out of them