I thought the prevailing meta for why Russia attacked Ukraine was that there is a window of opportunity that is rapidly shrinking and if they don't do it now, R

I thought the prevailing meta for why Russia attacked Ukraine was that there is a window of opportunity that is rapidly shrinking and if they don't do it now, Russia will never be able to do it again. If China PR believes the same, we have big problems. My hope is that the Xi administration believes that going to war and losing will cause them to lose power to domestic mainland opportunists. It might be naive but then couldn't we say the same thing about mutually assured destruction (mad)?