On top of this, Russia gets a free chip in any other diplomatic negotiations its involved in. They offer to remove troops and de-escalate the situation in return for some gain elsewhere. After their gain is secured, they can begin building up troops again and do the play all over again. The US and its allies will of course complain, but they actually benefit from this too, as it justifies their involvement in the situation and they score a political victory at home every time they get Russia to back down. It is remarkable how stabilizing regularly occurring crises can be.