Keeping a significant portion of your army (including blood supplies https://www.reuters.com/world/us-says-russia-inching-troops-closer-ukraine-stocking-up-blood-supplies-2022-02-17/) costs a lot of money. They weren't there for a vacation, this was the plan all along. I didn't believe it myself, thought that Putin would make the West look like fools. Well guess what, the western intelligence agencies were right for once.