One would have thought that the Russians would know this better than anybody after the USSR's collapse but military might is meaningless if you don't have the economic might to back it up.

Russia is little more than a petro state whose economic fortunes are almost completely related to the price of oil.

Putin should be focusing on broadening the Russian economic base but is instead engaging in stupid military endeavors that are only kidding Russia friends. The EU would love to trade with Russia but his European tinkering had made it impossible for them to do so. The US is obviously not a fan. Give it a few years and he'll probably piss off China too (or they'll find the US and European relationships more useful) and the Ryssians will have little more to do than reminisce about the time they annexed Crimea.