He probably didn’t think Putin would be completely insane, or that China would be in such complete chaos, with Xi likely being removed from power and their economy circling the drain. It’s not productive to make judgments about complex, long term dynamics with a very short view.
It’s a little like no battle plan surviving the first shot being fired - things don’t go as anticipated and some executive skill and experience needs to be put to work, adapting as many times as necessary to hopefully get a reasonably good result. We can be very grateful we don’t have the flagrantly incompetent alternative in the White House.