From Habsburg Spain to Trump’s America, there’s no escaping the consequences of spending more on interest payments than on defense.
In the ancient Hellenic world, hubris was the kind of pride or arrogance that led a mortal to defy the gods. But hard on its heels there usually came Nemesis, the goddess of divine retribution. The historian prefers to exclude deities from his narrative. He discerns the more prosaic operation of budgetary constraints. For it is these, not gods, that set limits on the geopolitical ambitions of republics and empires alike.
What I call Ferguson’s Law states that any great power that spends more on debt service than on defense risks ceasing to be a great power. The insight is not mine but originates with the Scottish political theorist Adam Ferguson, whose “Essay on the History of Civil Society” (1767) brilliantly identified the perils of excessive public debt.