The diplomatic framework governing the Strait of Hormuz cannot be analyzed through the lens of static bilateral agreements. When Tehran asserts that no structural guarantees exist for United States diplomatic commitments, it is not merely issuing a rhetorical grievance; it is stating a baseline assumption of international relations theory. In an anarchic international system, state actors operate under the principle of self-help, where agreements are enforceable only as long as the underlying power dynamics remain stable. Iran’s declaration that the Strait of Hormuz belongs exclusively to regional littoral states is a strategic attempt to reframe an international shipping lane as a sovereign security zone, shifting the geopolitical equilibrium.
To understand the current friction, one must analyze the strategic calculus of both Washington and Tehran through formal operational frameworks. The impasse is driven by two structural elements: the Commitment Problem in asymmetric diplomacy, and the Legal Elasticity of maritime chokepoints under international law.
The Strategic Architecture of Chokepoint Control
The Strait of Hormuz is the world's most critical energy conduit, handling approximately 20% of global petroleum liquids consumption and a significant portion of liquefied natural gas (LNG) trade. Because of this high concentration of economic value, control over the waterway operates under a specific cost function.
The primary variable driving this function is the asymmetric cost of disruption. For Iran, the marginal cost of closing or harassing traffic in the strait is relatively low, achieved via asymmetric naval assets such as sea mines, fast attack craft, and shore-based anti-ship cruise missiles. Conversely, the marginal cost for external actors like the United States to secure the strait requires continuous, capital-intensive power projection, including carrier strike groups and mine-countermeasure operations.
This asymmetry creates a structural temptation for Tehran to use its geographic leverage. However, this leverage is bound by an economic feedback loop:
$$C_{\text{disruption}} = E_{\text{sanctions}} + M_{\text{retaliation}} - L_{\text{leverage}}$$
Where:
- $C_{\text{disruption}}$ is the net cost to Iran for altering traffic in the strait.
- $E_{\text{sanctions}}$ represents the economic drag of retaliatory Western sanctions.
- $M_{\text{retaliation}}$ represents the direct kinetic costs of a military response from the United States or regional allies.
- $L_{\text{leverage}}$ represents the diplomatic and economic concessions Iran can extract by threatening the flow of energy.
When Tehran claims that regional states are the sole guardians of the strait, it seeks to maximize $L_{\text{leverage}}$ while minimizing $M_{\text{retaliation}}$ by decoupling regional security from global oversight. By asserting that the maritime highway is a domestic or regional condominium, Iran attempts to delegitimize the presence of external naval forces, specifically the U.S. Fifth Fleet, framing their operations not as freedom of navigation enforcement, but as unlawful intervention.
The Mechanics of the Commitment Problem
The Iranian assertion that the United States offers "no guarantees" highlights a fundamental concept in game theory: the time-inconsistency problem. A state actor cannot credibly commit to a long-term strategy today if its incentives change tomorrow.
From the perspective of Iranian policymakers, recent diplomatic history confirms this structural reality. The unilateral withdrawal of the United States from the Joint Comprehensive Plan of Action (JCPOA) in 2018 demonstrated that executive agreements lack institutional permanence across changing American presidential administrations. This structural volatility prevents Tehran from accepting verbal or political assurances from Washington as durable assets.
This lack of trust alters the bargaining dynamic in three distinct ways:
- Premium on Tangible Assets: Because promises of future sanctions relief are easily reversed, Iran demands immediate, upfront concessions that cannot be easily clawed back, such as the unfreezing of capital or the permanent removal of specific structural sanctions.
- Leverage Preservation: Iran cannot fully dismantle its leverage—whether its nuclear enrichment infrastructure or its ability to disrupt shipping in the Strait of Hormuz—because these assets are its only insurance policy against a future U.S. policy reversal.
- Calculated Escalation: To verify the boundaries of American deterrence, Iran engages in periodic, low-level testing of maritime norms. This provides real-time data on the risk tolerance of the current U.S. administration.
This structural reality creates a strategic bottleneck. The United States cannot legally bind future administrations to an international agreement without a two-thirds Senate majority for a formal treaty—a political impossibility in the current polarized environment. Consequently, any framework negotiated between Washington and Tehran is built on a foundation of temporary transactional arrangements rather than durable institutional commitments.
Legal Ambiguity and the United Nations Convention on the Law of the Sea
The geopolitical struggle over the Strait of Hormuz is fundamentally a conflict over legal definitions. The core of the issue lies in the tension between the United Nations Convention on the Law of the Sea (UNCLOS) and the domestic legislation of littoral states.
The Strait of Hormuz is an international strait, but its narrowest point is only 21 nautical miles wide. Because territorial waters extend up to 12 nautical miles from a country's coast under international law, the shipping lanes within the strait fall entirely within the territorial waters of Iran and Oman.
Under UNCLOS Part III, international straits are governed by the regime of transit passage. This legal framework grants all ships and aircraft—including military vessels—the freedom of navigation or overflight solely for the purpose of continuous and expeditious transit. Under transit passage, littoral states cannot suspend, hamper, or impose tolls on passing international traffic.
However, a significant legal vulnerability complicates this framework:
- Non-Ratification Dynamics: The United States has signed but never ratified UNCLOS, relying instead on the argument that freedom of navigation and transit passage are established principles of customary international law.
- Iranian Domestic Law: Iran has signed UNCLOS but has not ratified it. Tehran maintains that the right of transit passage is a purely conventional right enjoyed only by states that are full parties to the treaty. For non-parties like the United States, Iran recognizes only the more restrictive regime of innocent passage.
- The Restrictions of Innocent Passage: Unlike transit passage, innocent passage allows a coastal state to suspend transit if it deems the passage prejudicial to its peace, good order, or security. Furthermore, innocent passage requires submarines to navigate on the surface and show their flag, and it prohibits military activities such as launching aircraft or conducting weapons drills—restrictions that directly challenge U.S. naval operational doctrines.
When Iran asserts that "Hormuz belongs to coastal countries," it is attempting to enforce its domestic interpretation of maritime law over global customary law. This legal strategy aims to normalize a regime where permission, notification, or coordination with the Persian Gulf Strait Authority becomes a requirement for transit, effectively turning an international chokepoint into a sovereign toll zone.
Regional Alliances and Fragmented Security
Tehran’s strategy to shift responsibility for the strait to coastal countries is designed to exploit political divisions within the Gulf Cooperation Council (GCC). By framing security as a shared duty among littoral states, Iran attempts to present regional monarchies with a difficult choice: accept a security framework dominated by Tehran, or continue relying on Western military forces at the risk of constant regional instability.
This strategy faces a major obstacle: the divergent threat perceptions of the coastal states.
The United Arab Emirates and Saudi Arabia have spent decades integrating their security architectures with the United States. However, their economic dependence on uninterrupted maritime transit makes them highly vulnerable to conflict. A full blockade or prolonged kinetic escalation in the strait would quickly halt oil exports, spike insurance premiums for commercial vessels, and disrupt global supply chains.
Aware of these vulnerabilities, smaller littoral states like Oman often adopt a hedging strategy. Muscat maintains close diplomatic ties with both Washington and Tehran, frequently acting as a mediator. By engaging in bilateral discussions with Iran regarding maritime coordination, Oman seeks to prevent miscalculations that could lead to a broader conflict. However, this diplomatic balancing act can inadvertently weaken the unified front that the United States tries to maintain among its regional partners.
Escalation Pathways and the Strategic Recommendation
Given these structural dynamics, the geopolitical situation in the Strait of Hormuz cannot be resolved through a traditional, comprehensive treaty. Instead, the relationship will likely remain a series of managed crises, short-term ceasefires, and transactional arrangements.
The most effective strategy for international maritime actors is not to pursue unenforceable long-term political commitments, but to focus on establishing clear operational boundaries.
- Enforce Operational Deterrence: To counter attempts to normalize a sovereign toll system in the strait, international coalitions must consistently conduct freedom of navigation operations (FONOPs). Any effort to require prior notification or coordination for transit must be met with non-compliance to prevent Iranian claims from hardening into recognized customary law.
- Establish Practical Communication Channels: To reduce the risk of accidental escalation, Washington and Tehran need direct, reliable communication links between their operational naval commands in the Gulf. This helps prevent localized incidents between fast attack craft and commercial vessels from turning into a broader regional conflict.
- De-Risk Infrastructure: Regional economies must reduce their vulnerability to the Strait of Hormuz by investing in alternative energy export routes. This includes expanding cross-peninsula pipelines, such as Saudi Arabia’s East-West Pipeline and the UAE’s Habshan–Fujairah pipeline, to move oil directly to the Red Sea or the Arabian Sea, bypassing the chokepoint entirely.
Ultimately, reducing Iran’s leverage over the Strait of Hormuz requires altering the cost-benefit equation of disruption. As long as global markets remain highly sensitive to traffic through the strait, Tehran will continue to use its geographic position to offset its economic and military disadvantages. True maritime security in the region will be achieved not through signed declarations, but by building infrastructure that reduces the strategic importance of the chokepoint itself.
