MADRID – The joint American and Israeli assault on Iran, launched on February 28, 2026, was conceived as a demonstration of decisive force. Air superiority, applied with precision and persistence, was expected to compel Tehran into submission or, at minimum, to degrade its capacity to shape events in the Persian Gulf. Four weeks later, that premise appears increasingly detached from realities at sea.

The Strait of Hormuz, through which a fifth of globally traded oil normally circulates, has not been formally closed, yet it has been rendered functionally inoperative for many ships. What has come undone is not simply a military plan, but a broader system in which power has long been equated with the ability to guarantee circulation.

At its narrowest point, the strait spans just 33 kilometres, with deepwater shipping lanes running closer to Iran’s coastline than to the Arabian Peninsula. In 2025, roughly 20 million barrels per day passed through this corridor. By mid-March 2026, that figure had fallen sharply, with only a limited number of tankers attempting the crossing. The disruption has not taken the form of a declared blockade. There are no continuous lines of interdiction, no visible barriers to passage. Instead, Iran has introduced calibrated uncertainty into the environment through which ships must pass. Drones operate from Qeshm Island, monitoring movement and signalling presence. Missile launches remain intermittent, yet credible enough to alter calculations.

The effect has been cumulative rather than spectacular. Tankers are not routinely destroyed, but they do not need to be. The contemporary global economy depends less on the possibility of movement than on its predictability. Once Lloyd’s of London withdrew war risk insurance from large parts of the route, and premiums rose to levels that shipowners could not absorb, transit effectively ceased. The strait has been closed not by legal declaration or physical obstruction, but through the repricing of risk.

This distinction marks a shift in how power is exercised. Rather than asserting territorial control in a conventional sense, Iran has altered the conditions under which circulation occurs. The management of uncertainty becomes the central mechanism. Air strikes, however precise, do little to restore confidence in such an environment. They can destroy infrastructure and eliminate personnel, but they cannot easily reverse a situation in which the cost of movement has become prohibitive.

Statements from Tehran suggest that this approach is neither improvised nor reactive. In his first address, Leader of the Islamic Revolution Ayatollah Seyyed Mojtaba Khamenei described the strait as a lever through which broader pressures could be applied. American planning appears to have rested on the assumption that Iran’s dependence on oil exports would act as a restraint. That assumption reflects a narrow understanding of economic rationality. It privileges volume over position, overlooking the extent to which influence over the terms of circulation can outweigh temporary losses in output.

The immediate economic consequences are visible but uneven. Oil prices have risen to around $118 per barrel, generating windfalls for some producers while imposing costs on consumers. American firms benefit from higher prices, even as domestic fuel costs increase. High prices expose the enduring centrality of Persian Gulf energy to the global economy, underscoring how attempts to marginalise Iran have only deepened systemic dependence on the region it helps anchor. At the same time, they enhance the relative attractiveness of alternative technologies, particularly those produced at scale in China, whose expansion increasingly aligns with energy realities shaped in part by Iranian leverage. Yet substitution remains constrained by infrastructure, geography and time, reinforcing the limits of any strategy that seeks to bypass rather than accommodate Iran’s role.

More significant than price movements are the transformation in how the strait is understood. For decades, it has been treated as a neutral conduit, a space of transit secured by American naval dominance and open to all participants in the global market. That neutrality was always contingent on the absence of effective challenge. It is now openly contested. Iran has not replaced the system, but it has exposed its underlying assumptions and demonstrated their fragility.

Circulation, risk, and the littoral

Iran’s strategy in the strait draws on a long-developed doctrine of littoral warfare, in which geography and proximity are leveraged to offset conventional inferiority. The shallow waters, confined channels and island networks of the Persian Gulf favour dispersed systems over concentrated force. Drones, fast attack craft and naval mines operate not as instruments of decisive engagement, but as tools for introducing friction into movement.

The objective is not to defeat the United States Navy outright, but to render its presence insufficient to guarantee passage. A navy can dominate open waters while remaining unable to secure narrow, contested corridors in which risk is distributed and difficult to eliminate. In such environments, the cost of assurance rises rapidly.

Insurance markets have become the decisive arena in which this cost is expressed. Premiums for transit have increased multiple times over, in some cases surpassing the value of the vessels themselves. Crews face heightened exposure without corresponding compensation. Shipowners delay voyages or seek alternatives where possible. The infrastructure of trade begins to stall, not because it has been destroyed, but because it can no longer operate under predictable conditions.

This form of disruption is inherently selective. Iran does not impose a total blockade. Instead, it allows certain vessels to pass while obstructing others. Reports indicate that Chinese flagged tankers have continued to move with fewer impediments, and that cargoes denominated in non-dollar currencies may receive preferential treatment. Whether fully systematised or evolving, such practices introduce differentiation into what has historically been presented as a uniform system of access.

The implications extend beyond shipping. The predominance of the dollar in global energy trade has long underpinned American financial power, enabling sanctions to function as instruments of coercion. By linking maritime access to alternative payment arrangements, Iran is not displacing this system but probing its limits. Even incremental shifts in settlement practices, when tied to physical control overflows, carry disproportionate significance.

The strait thus emerges as more than a geographic bottleneck. It is a site where logistics and finance intersect, where the movement of goods is inseparable from the systems that price and ensure that movement. Control in this context does not require exclusivity. It requires sufficient influence over risk to shape behaviour.

The historical formation of this space remains relevant. The Persian Gulf’s shipping lanes were structured through imperial intervention, first under British authority and later through American naval dominance. Ports, pipelines and security arrangements were designed to ensure outward flows of hydrocarbons while embedding regional economies within external circuits of accumulation. The notion of a global commons, applied to these waters, obscures the extent to which access has always been managed.

Iran’s actions do not dismantle this inherited system, but they interrupt its smooth functioning. By operating at the level of probability rather than prohibition, Tehran introduces a form of control that is difficult to counter without escalation. The burden of disruption is unevenly distributed. Tanker crews, often drawn from migrant labour pools, face immediate physical risk. Port workers and ancillary industries experience volatility. Insurance firms adjust exposure and transfer costs. What appears as strategic manoeuvre at the state level translates into differentiated forms of vulnerability across the chain of circulation.

The limits of force and the reconfiguration of order

The American response has exposed the constraints of a strategy centred on military superiority. Carrier groups remain deployed in the region, and air strikes continue against Iranian targets. Yet the fundamental objective, the restoration of predictable passage through the strait, has not been achieved. Efforts to assemble a multinational escort operation have faltered, reflecting diverging interests and the risks associated with escalation.

European allies have shown little appetite for direct involvement. Persian Gulf states, while affected by the disruption, remain cautious about provoking further instability. China, as a principal importer of Persian Gulf energy, has little incentive to participate in an arrangement that might compromise its bilateral channels with Tehran. The absence of a coherent coalition underscores the fragmentation of what has often been assumed to be a unified maritime system.

Historical precedents offer limited reassurance. The escort operations of the late twentieth century required extensive preparation and cooperation, and still incurred losses. The current environment is more complex, with a wider array of actors capable of projecting force across different domains. Groups aligned with Iran extend the geography of risk beyond the strait itself, raising the potential costs of any attempt to impose a purely military solution.

Within Washington, policy signals have lacked consistency. Statements threatening expanded strikes coexist with discussions of releasing strategic reserves and calls for restraint. This oscillation reflects uncertainty about both objectives and means. Restoring circulation requires more than suppressing immediate threats. It depends on re-establishing confidence among commercial actors, a task that cannot be accomplished through force alone.

Iran, for its part, continues to operate within constraints while demonstrating an ability to convert them into leverage. Its own exports have declined, but they have not ceased. Alternative routes, intermediaries and elevated prices mitigate losses. More importantly, the disruption reinforces the extent to which regional stability cannot be sustained without its participation. Exclusion proves costly not only for Iran, but for the system as a whole.

The broader consequences are already visible. Energy importing economies in Asia face renewed volatility. European states confront supply constraints that revive concerns over dependency. Persian Gulf producers accelerate efforts to expand pipeline infrastructure, though geography imposes limits on what can be achieved. Quiet diplomatic engagement with Tehran suggests recognition that the current configuration is unsustainable.

At the level of perception, the shift may be more profound. The image of an open Persian Gulf, secured by American power and integrated into a stable global market, has been central to the postwar order. The present disruption does not dismantle that order, but it reveals its contingency. Control over circulation appears less absolute, more subject to negotiation and interruption.

Iran’s actions illustrate a form of power that operates through the modulation of flows rather than their outright denial. By introducing uncertainty into a system that depends on predictability, it has altered the relationship between military capability and economic effect. The Strait of Hormuz, long described as a vulnerability, emerges instead as a site of leverage, where geography, infrastructure and strategy converge.

For the United States, the lesson extends beyond the immediate conflict. Military power can shape outcomes in defined engagements, but it is less effective in securing the infrastructures and expectations that sustain global circulation. Where those infrastructures are exposed to disruption, and where expectations can be unsettled, power becomes diffuse and contested.

The Persian Gulf is therefore not simply a theatre of confrontation. It is a space in which logistics, finance and sovereignty intersect, and where the terms of movement are continuously negotiated. In that space, Iran has demonstrated an ability not only to resist pressure, but to reshape the conditions under which the system itself operates.