The Strait of Hormuz has never been closed. The threat of closure has been used repeatedly as a diplomatic instrument by Iran, and incidents in the strait have periodically elevated insurance premiums, rerouted tankers, and spiked oil prices. What has not happened, in the modern era of global oil dependence, is a complete cessation of transit. This absence of precedent does not mean the scenario is implausible. It means that the consequences of closure must be modeled rather than observed, and the models are sobering.

Iran’s nuclear program and the Strait of Hormuz are connected through a logic that diplomatic analysis frequently understates. The connection is not simply that a nuclear-armed Iran would be more willing to close the strait — though that proposition has its own merit. It is that the negotiations over the nuclear program, the sanctions imposed to pressure it, and the diplomatic settlements that have attempted to resolve it are all embedded in the same geopolitical relationship that determines whether the strait operates as a commercial corridor or a conflict zone. The nuclear file and the Hormuz file are the same file.