There's no way to maintain the empire and also preserve access to China's minerals. They either need to capitulate and negotiate with China (unacceptable because it ends their domination) or they need to start a war to occupy strategic resources (which we both agree won't work). Their fascism is actually a response to the irreversible decline of their empire, it's the only choice remaining that doesn't involve admitting defeat.

It only delays the inevitable, but it does delay it. This is where the gerontocracy plays a role: it's rational for an 80+ imperialist to delay the decline of the empire, because when it inevitably implodes they'll be dead anyway and they hate their children so who cares?