The world’s most important energy chokepoint shut down not by missiles but by spreadsheet.
As Shanaka Anselm Perera argues in “The Insurance Siege: How Insurance Markets, Not Missiles, Closed the Strait of Hormuz,” the decisive move came not from navies but from insurers. Seven P&I clubs pulled war-risk coverage. Tanker traffic collapsed 80% in 48 hours. No mines required — just actuaries doing math.
Perera called this mechanism before Trump confirmed it live. At 2:37 PM EST on Tuesday, March 3rd, the President ordered the U.S. Development Finance Corporation — a development bank most people have never heard of — to provide political-risk insurance for Gulf shipping. Not an airstrike. Not sanctions. An insurance product. If the problem were military, the response would have been military. The White House just told you the chokepoint is financial infrastructure.
But the gap between announcement and reality is the whole game. The DFC has never underwritten maritime war-risk insurance. The P&I clubs that do spent decades building the models, capital, and claims infrastructure — and walked out in 72 hours once the risk became un-modellable. The DFC’s total political risk insurance book is $7.3 billion. The daily value of oil transiting Hormuz is $2 billion. The math doesn’t math.
The market hears “effective immediately.” The insurance industry hears “we’ll get back to you.”
What the Crowd Gets Right and Wrong
Polymarket understands the war: 62% ceasefire by March 31, 81% conflict ends by June, 8% ground invasion. The military clock runs 4–8 weeks. Probably correct.
The Hormuz closure curve is where it breaks: 66% by March, 68% by June, 73% by December. That’s seven points across nine months. The crowd treats reopening like a light switch — it either happens or it doesn’t, and timing barely matters.
Perera’s insight is that it’s not a switch. It’s a dimmer controlled by reinsurers who need a stable counterparty to model against. With 63% regime change odds, 35% coup probability, and 440.9 kg of unaccounted nuclear material, there is no stable counterparty. The last comparable insurance market freeze — repo collateral, 2008 — took 14 months to unwind.
A ceasefire ends the shooting. It doesn’t reinstate the coverage.
Sell-side oil forecasts are typically conditioned on kinetic duration. How long the bombs fall. None model actuarial duration. How long it takes the P&I clubs to come back. Energy desks and insurance desks don’t talk to each other.
Perera’s paper sits in that seam. And as of this week, so does the White House — whether it knows it or not.
Click here to interact with the Hormuz Actuarial Blockade Stress Tester.
