he second, and much bigger obstacle, is the assumption that Russia will take it all lying down. It is a dangerous assumption, as already noted by analysts, and a costly one, as reported by JP Morgan, which has estimated that if Russia decides to cut exports in response to the cap, oil could soar to $380 per barrel.
https://oilprice.com/Energy/Energy-General/Why-Putting-A-Price-Cap-On-Russian-Oil-Wont-Work.html