This how empires collapse:

- To maintain fellowship, the empire spreads money to buy influence

- eventually this starts to cost too much, so the empire reduces spending

- wars ensue and independent voices emerge

- unable to establish order, the empire loses its influence and collapses

You can see this patterns as the US is overspending (high debt / trade deficit) while reducing its diplomatic influence on international programs. Not sure how they can save the USD value over time.