If there is no real difference, whether you say the empire has fallen or not is just a semantic thing.

The difference is whether the military dominates and whether the currency dominates.

If you are wondering whether the still-powerful miliary would take actions to ensure that the less-powerful currency continues to dominate, then that is an interesting question. I think the answer is probably yes. Some people interpret American military interventions as a defense of dollar hegemony, and ignore the claimed reasons.