Three small islands sit near the entrance of the Strait of Hormuz. Abu Musa belongs to the emirate of Sharjah. Greater Tunb and Lesser Tunb belonged to Ras al-Khaimah. In November 1971, two days before the British protectorate over the Trucial States expired and three days before the United Arab Emirates came into formal existence as an independent nation, Iranian forces occupied all three. Greater Tunb was taken by force, killing several Ras al-Khaimah police officers who attempted to resist. Abu Musa was occupied under a memorandum of understanding with Sharjah that Iran has since interpreted in ways that effectively amount to full occupation. The UAE has never accepted any of this. The dispute is over fifty years old and shows no sign of resolution.

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.

Iran operates submarines in the Strait of Hormuz and the broader Gulf of Oman. The fleet is not large, and the vessels are not modern by the standards of major naval powers. What they represent is a persistent underwater presence in one of the world’s most difficult antisubmarine warfare environments — a shallow, thermally layered, acoustically cluttered body of water where detection is genuinely hard and where even a small submarine with limited capability poses a disproportionate threat to shipping and to surface naval forces.

A tanker that does not appear on tracking screens is not invisible. It is simply operating in the gap between the legal obligation to broadcast its position and the practical inability of enforcement authorities to impose consequences for failing to do so. Iran has exploited that gap systematically and at scale, building a sanctions evasion infrastructure that has kept its oil revenues flowing through periods when official exports were near zero, and learning, in the process, the operational techniques of maritime concealment that have military implications beyond their immediate commercial function.

The 2019 attack on the Abqaiq oil processing facility used cruise missiles and drones. The subsequent attacks on tankers in the Gulf of Oman used limpet mines and, in some cases, explosive-laden fast boats. By the time Houthi forces began their Red Sea campaign in late 2023, the weapons mix had evolved to include one-way attack drones and ballistic missiles fired against commercial vessels. The technological trajectory is consistent: unmanned systems are becoming a larger share of the threat to shipping in and around the Persian Gulf, and their characteristics — low cost, deniability, saturation potential, and steadily improving accuracy — make them a structural shift rather than a tactical adaptation.

Israel does not import oil through the Strait of Hormuz. Its energy supply arrives primarily through the Ashkelon terminal from the Caspian pipeline system and through domestic production from offshore Mediterranean fields that have grown substantially over the past fifteen years. Israel’s direct exposure to Hormuz transit is limited. Its indirect exposure — through the price effects of any closure, through the regional security consequences of US-Iran conflict, and through the impact of Iranian military capacity on the deterrence calculus that Israel maintains — is substantial and persistent.

The Musandam Peninsula is an exclave of Oman separated from the rest of the sultanate by a strip of UAE territory. It juts northward into the Gulf, forming the southern jaw of the Strait of Hormuz. Iran’s coastline forms the northern jaw. Between them is the corridor through which the global oil trade flows. Oman is the only country in the world that shares a maritime border with Iran along the strait, and this geographic fact has given the sultanate a diplomatic role that its size and military capacity would not otherwise justify.

Pakistan sits at the northeastern corner of the Arabian Sea, flanked by Iran to its west and with a coastline that extends from the Gulf of Oman toward India. It is the world’s only nuclear-armed Muslim-majority state, a country with deep financial and demographic ties to the Gulf Arab states, and a country with a 900-kilometer land border with Iran. Its position makes it relevant to every major regional security scenario, including Hormuz, without giving it decisive influence over any of them. Pakistan is courted and pressured simultaneously by parties whose interests in the Gulf are incompatible, and it manages this position with a hedging strategy that satisfies no one and infuriates everyone.

Iran has invested more systematically in anti-ship missile capability than any other aspect of its naval force development over the past three decades. The investment reflects the operational logic of the IRGCN’s Hormuz doctrine: surface ships and tankers transiting the strait in a contested environment must be threatenable from multiple vectors simultaneously, and missiles — launched from shore, from surface vessels, from aircraft, and eventually from submarines — provide the most cost-effective way to achieve that coverage. The resulting arsenal is among the largest and most diverse anti-ship missile inventories of any regional power.

The March 2023 agreement restoring Saudi-Iranian diplomatic relations, brokered in Beijing over four days of talks that surprised most Western analysts by the speed and apparent completeness of their outcome, was described at the time as a potential transformation of Gulf security dynamics. The more accurate framing is that it was a managed reduction in operational hostility between two states whose fundamental interests remain incompatible and whose competition for regional influence has been paused, not resolved. The strait has been somewhat quieter since the agreement. The conditions that make it dangerous have not changed.

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.

The strategic partnership between Russia and Iran has been deepening since 2022 in ways that have direct implications for the Persian Gulf security environment. The relationship is not an alliance in the formal sense — no mutual defense treaty binds Moscow and Tehran, and the two countries have a long history of friction and competing interests that did not disappear when their shared confrontation with the West provided new incentives for cooperation. What has emerged is something more specific: a bilateral relationship structured around shared sanctions exposure, complementary military needs, and converging interests in reducing American influence in the regions that matter to each of them.