It was Les Aspin under Bill Clinton who guided the DOD to no longer be able to fight two major conflicts ... they lied about it, of course.
You are right about the timing. It did happen under Clinton. Our ability was reduced.
Officially the policy was never changed though. Our stated goal/duty was to keep a two theater lever of preparedness.
I had hoped Bush would repair, and get us back to the two theater setting.
What he did was officially change the policy.
It was Bush that officially changed our strategic preparedness to that of a one theater stance.
This was just one more reason I despised the guy.