At the Palace of Versailles on Wednesday, Donald Trump pointed to the financial markets as the ultimate verdict on his Iran agreement. "There is nothing as smart as the market — and the market loves it," he declared, as crude oil slipped below $80 a barrel for the first time since the opening salvos of a conflict he had launched in late February. The price drop was real, and so was the relief it signalled: with roughly 20% of the world's oil supply routed through the Strait of Hormuz, every day that passage remained blocked had been costing importing economies dearly. Yet by the weekend the diplomatic architecture was already showing stress fractures.

Planned peace talks in Switzerland were cancelled and then hastily revived; Iran cited Israeli strikes in Jordan as justification for threatening to close the strait once more. Analysts who had warned of acute jet-fuel shortages if the war dragged on found their projections uncomfortably relevant again. Whether the strait fully reopens in the days ahead remains the single question on which the near-term trajectory of global energy markets depends. The human cost of the uncertainty is distributed with striking inequality.

Gulf economies — whose principal export was throttled and whose cities absorbed Iranian ordnance — are heading into recession.