The Supreme Leader of the Islamic Republic of Iran is eighty-five years old. His health has been the subject of sustained speculation for years, with periodic reports of serious illness that the Iranian government neither confirms nor adequately denies. The succession question is not speculative. It is operational. The individuals and factions positioning for post-Khamenei influence are doing so now, and their relative strength when the transition occurs will determine whether the Islamic Republic emerges from succession in a more confrontational or more accommodating posture toward the outside world, and toward Hormuz specifically.

The Islamic Revolutionary Guard Corps Navy does not train to defeat the United States Navy in open water. It trains to make the cost of operating in the strait prohibitive. These are different strategic problems with different solutions, and the IRGCN has spent four decades refining the second one while ignoring the first.

The doctrine that has emerged from this period is sometimes called asymmetric maritime warfare, which is accurate as far as it goes. What the label understates is the geographic specificity of the strategy. The IRGCN is not a general-purpose force. It is a Hormuz force. Every element of its order of battle — the fast attack craft, the anti-ship missile batteries, the submarine fleet, the mine warfare capability, the shore-based artillery — is oriented around the same twenty-one-mile problem.