Sanctions, oil and the limits of pressure

Sanctions are the instrument of choice because they are the only one that can be applied without a vote to go to war. Their track record is not empty, but it is narrower than the policy debate implies, and the gap has widened as the plumbing of evasion has industrialised.

What actually happens to the barrels

Discounted crude finds buyers. A shadow fleet of ageing tankers, opaque ownership chains and ship-to-ship transfers moves it. Payment routes around the dollar through intermediaries with limited exposure to Western enforcement. The result is a revenue haircut rather than a revenue stop, and the haircut is absorbed disproportionately by the population rather than the state.

Sanctions reliably impose cost. Whether cost translates into a change of behaviour is a separate question, and one the evidence answers less kindly.

The enforcement treadmill

Each round of designations produces adaptation, which produces the next round. The system is not static, and the cumulative effect is real: older vessels, higher spill risk, thinner insurance, more accidents. The environmental tail risk of the shadow fleet is underpriced and mostly ignored.

Secondary sanctions and the dollar

The most powerful tool is also the one that erodes with use. Every large buyer that builds a non-dollar settlement route for sanctioned energy builds infrastructure that stays built. The near-term cost of using the instrument is low and the long-term cost is a slow reduction in its potency.

What to watch

The discount on sanctioned grades, insurance and freight spreads, the pace of new vessel designations, and whether refiners in large importing economies begin to price the compliance risk into their contracts. That last one is the signal that enforcement is biting.