You're greatly overestimating the late-stage empire. The brinkmanship and provocation aren't part of some plan, they're just ordinary imperialism. What has changed is the empire is too unstable to enforce its own hegemony and so preexisting enemies of the empire have been able to strike major blows against it.

Soft power is dead. Military power is all that's left. The empire is not in control of any of these conflicts and is on the back foot.