Right now, the United States is spending more money to service its national debt than it spends on its entire military.
Let that sink in.
Interest payments on the U.S. national debt are set to surpass $1 trillion in 2026. That is $88 billion a month.
It is equal to our spending on defense and education combined.
At the exact same time, the Pentagon has burned through $24 billion worth of major munitions in just the first seven weeks of the Iran war.
We have depleted 50% of our Terminal High Altitude Area Defense (THAAD) interceptors and almost half of our Patriot ballistic interceptor missiles.
We are firing $4 million missiles to shoot down $20,000 drones.
And military experts warn it could take up to four years to rebuild those stockpiles.
We are watching the financial and military exhaustion of a superpower in real-time.
But this is not the first time a global hegemon has spent itself into a corner where its debt eclipsed its defense.
The Empire Where the Sun Never Set
In the 16th century, Spain was the undisputed master of the world.
Under King Philip II, the Spanish Empire stretched from the Americas to the Philippines. They controlled the oceans. They commanded the most feared military force on earth.
And they had a seemingly endless supply of wealth pouring in from the silver mines of the New World.
But they also had a spending problem.
Philip II was fighting wars on multiple fronts. He was battling the Ottomans in the Mediterranean, suppressing a massive revolt in the Netherlands, and preparing to launch the great Spanish Armada against England.
To fund this global military footprint, Philip borrowed on an unprecedented scale.
He issued short-term, high-interest loans called asientos, and long-term bonds called juros.
He mortgaged the future of the empire to pay for the wars of the present.
By the 1590s, the situation had become mathematically impossible.
The disastrous Spanish Armada had cost 10 million ducats—nearly three times its original budget.
By 1595, Philip was spending 12 million ducats a year, acting as if the silver would never stop flowing.
The Mathematical Limit of Power
Historian Niall Ferguson calls it “Ferguson’s Law.”
It states a simple, brutal truth: Any great power that spends more on debt servicing than on defense risks ceasing to be a great power.
Spain hit that limit hard.
By the late 16th century, debt servicing was consuming between 40% and 50% of the Spanish crown’s annual revenue.
The debt burden drew scarce resources away from national security, leaving the empire increasingly vulnerable to military challenges.
The math always wins.
To keep the war machine running, Philip II introduced a crushing new tax called the millones.
It targeted basic foodstuffs—wine, meat, vinegar, and oil. It devastated the working class of Castile, driving up the cost of living and destroying the domestic economy.
But even taxing the food off his citizens’ tables wasn’t enough.
In November 1596, the Spanish crown was declared bankrupt. It was the fourth default of Philip’s reign, and the most devastating.
The empire that controlled the world’s wealth could no longer pay its bills.
The Echo Across Centuries
The parallels to our current moment are chilling.
Spain’s decline didn’t happen overnight. It was a gradual process of financial and military attrition.
They didn’t invest in their domestic economy; they just continued to extract wealth and borrow against it to fund overseas conflicts.
Today, the U.S. national debt sits at $39 trillion.
We are issuing debt at record levels just to pay the interest on the debt we already owe.
And just like Spain, we are discovering that military supremacy is an illusion when you can’t afford to replace the weapons you fire.
When a nation hits the Ferguson limit, history shows that strategic rivals will inevitably challenge its position.
Spain lost the Netherlands. They lost their aura of invincibility. Within a generation, they were eclipsed by the Dutch and the British.
They ceased to be a great power.
We are currently watching the exact same mathematical trap close around the United States.
5 Things You Can Do This Week
When empires overextend themselves financially and militarily, the burden always falls on the citizens. Here is how you can prepare your household for the economic realities ahead:
1. Reduce Your Personal Debt Exposure
When national debt spirals, inflation and taxation are the only ways governments can pay for it. Eliminate variable-rate debt and consolidate what you owe. Do not let the government’s spending problem become your personal bankruptcy.
2. Build a Tangible Asset Base
Spain’s citizens suffered when the crown repeatedly defaulted and devalued the currency. Move a portion of your wealth into tangible assets—precious metals, land, or productive equipment—that cannot be printed or defaulted on by politicians.
3. Audit Your Supply Chains
As military spending crowds out domestic investment, infrastructure and supply chains become fragile. Identify the critical goods your family relies on (medications, specific foods, energy) and build a 90-day buffer.
4. Invest in Practical Skills
When the Spanish economy hollowed out, those with practical, localized skills survived best. Learn how to repair, grow, and maintain the things you own. The less you rely on complex, globalized systems, the safer you are.
5. Secure Your Food Production
Philip II’s millones tax targeted basic food items, crushing the middle class. Protect yourself from food inflation by starting a garden, supporting local farmers, or investing in long-term food storage. Food sovereignty is the ultimate hedge against imperial decline.
