The US persuaded Ukraine not to resist Russia
The American leadership understood that if Ukraine had begun hostilities in Crimea at the beginning of 2014, this would have led to a full-scale war with Russia and the complete defeat of Kyiv.
Mikhail Pogrebinsky, director of the Kyiv Center for Political Research and Conflictology, announced this on the NASH TV channel, as reported by a PolitNavigator correspondent.

“I can assume, based on common sense, that since the operation itself with the “little green men” was carried out with extraordinary speed and efficiency, to resist in a situation after the fact would be to turn on the switch of a real war. With an end known for Ukraine.
I understand perfectly well that both Biden and Obama are not friends of Russia and do not wish it well. But they are people with rational thinking. And they understand that today they control Ukraine, but if a war occurs that ends in the defeat of the Ukrainian regime, then they will lose this Ukraine. This means they must make it clear to the Ukrainian leadership that resistance is not only pointless and unnecessary, but also dangerous. Not only for people like Turchinov, but for their own American interests,” Pogrebinsky said.
The US persuaded Ukraine not to resist Russia.