On Monday, financial containment appeared to be winning.

The Nikkei rallied 2.88%. Oil, which had touched $119 on Brent, collapsed to the high $80s after Trump told CBS News that the war was “very complete, pretty much”. By Wednesday the IEA had announced the largest coordinated oil reserve release in its history: 400 million barrels from 32 member nations. The US contributed 172 million barrels from the SPR. Japan committed 80 million barrels, its first solo reserve release since 1978. Bessent unsanctioned Russian crude stranded on the water, creating additional supply at the stroke of a pen. G7 energy ministers convened in Paris. Trump declared victory.

Every financial tool in the kit was deployed that week. SPR releases. Sanctions waivers. Verbal intervention. Coordinated G7 action. Maritime reinsurance promises. The market briefly believed it.

By Friday, Brent was back above $100. The 10-year Treasury yield had risen to 4.26%, its highest in a month. The Nikkei closed the week at 53,820, below where the crisis week began. What happened between Monday’s relief rally and Friday’s capitulation tells you something structural about the hierarchy of forces in markets.

Mines happened.

On Tuesday, CNN reported that Iran’s IRGC had begun laying sea mines in the Strait of Hormuz. A few dozen had been deployed. Iran retains 80 to 90% of its small boats and mine-laying capacity, with an estimated stock of 2,000 to 6,000 naval mines. CENTCOM destroyed 16 mine-laying vessels, but the mines already in the water persist. On Wednesday, the UK Defence Secretary confirmed that reports of Iranian mining had become “clearer and clearer.”

The US Navy decommissioned its last four dedicated minesweepers in the region last September, leaving littoral combat ships to handle mine countermeasures. A naval mine expert at the Center for Naval Analyses observed that a hasty clearance, opening just one narrow lane, might take days. Reaching a safety level where commercial operators accept the risk could take weeks. Full clearance of the waterway could take far longer. There are still Second World War mines in the Baltic.

This is the structural lesson of the week. Financial tools manage price. They cannot manage physical access. The Strait of Hormuz handles roughly 20 million barrels per day, about a fifth of global supply. The problem is not the price of oil. The problem is that tankers physically cannot transit. Hormuz traffic has not exceeded five crossings per day since the war began, against a historical average of 138. The IEA itself conceded the point. Fatih Birol, announcing the 400 million barrel release, said the same day: the most important thing for stable flows is the resumption of transit through the Strait of Hormuz.

Four hundred million barrels sounds enormous. It is roughly four days of global production. Over 120 days at planned discharge rates, the US contribution of 172 million barrels works out to about 1.4 million barrels per day. The strait, when open, handles roughly 20 million. The maths does not work if the physical bottleneck remains closed.

Sea mines are the cheapest weapon in the Iranian arsenal. They cost thousands of dollars. A single mine strike on a VLCC is catastrophic, not because it sinks the vessel, but because it renders the waterway uninsurable. Major marine war-risk providers scrapped coverage for vessels in the Persian Gulf. Without insurance, ships do not sail. Without ships, oil does not move. Without oil moving, no volume of reserve releases changes the physical constraint.

The timeline distinction matters and most commentary has missed it. Before the mines, the Hormuz reopening timeline was coupled to the war timeline: if hostilities stop, traffic resumes. After the mines, the timelines decouple. Even a ceasefire tomorrow does not clear the strait. Minesweeping takes weeks under favourable conditions, longer if the minesweeping forces themselves face threats from Iranian shore-based missiles and drones. The oil disruption is no longer a function of the war. It is a function of the mines.

Bessent’s week illustrates the binding constraint. On Thursday March 6 he unsanctioned Russian crude to create supply. By Wednesday he helped orchestrate the largest reserve release in history. He announced maritime reinsurance backed by the US Development Finance Corporation. He stated Treasury would maintain a cadence of market-calming measures. On Thursday March 13, he authorised temporary purchases of all Russian oil stranded at sea, not just cargoes bound for India. Every lever available to a Treasury Secretary was pulled. Oil still ended the week above $100.

The hierarchy of forces, in descending order: physical military facts; financial intervention; verbal containment. Mines sit at the top of that hierarchy. They are indiscriminate, cheap, persistent, and psychologically devastating. They create uncertainty that no amount of reserve arithmetic can offset. A Treasury Secretary can unsanction barrels. He cannot unsanction a minefield.

The week’s price action was not a failure of policy. The SPR release, the sanctions waivers, the diplomatic coordination were all competent responses to a price shock. They would have been sufficient if the problem were a price problem. It was not. It was a physics problem. Four hundred million barrels of reserves cannot offset what a few dozen mines accomplished, because the reserves and the mines operate on different planes. One is financial. The other is physical. When they collide, physics wins.

You cannot SPR your way out of a minefield.

— Gyokuro

The views expressed here are the author’s own and do not constitute investment advice. This blog is independent, carries no affiliate links, and receives no compensation from any entity mentioned.