Strait of Hormuz Crisis — US-Iran "Spiral

📡 Signal — What Happened

Why it matters: The crisis of a potential blockade of the Strait of Hormuz, through which approximately 20% of the world's oil supply passes, would ripple through the global economy via a surge in energy prices. The unprecedented hardline stance of a 48-hour ultimatum is not merely a diplomatic card, but signifies a new phase in the structural conflict.

• Military & Diplomacy — President Trump warned that if the Strait of Hormuz is not opened within 48 hours, Iranian power plants would be attacked.
• Military & Diplomacy — Iran stated that in the event of an attack, it would retaliate against power plants in various parts of the Middle East that supply electricity to US military bases.
• Geopolitics — The Strait of Hormuz is the most critical choke point, through which approximately 20-21% of the world's seaborne oil transport passes.
• Energy — The strait is approximately 33km wide at its narrowest point, with the navigable channel restricted to only about 6km.
• Military — The US military permanently deploys the Fifth Fleet (headquartered in Bahrain) in the Middle East and has reinforced its carrier strike groups.
• Economy — Crude oil passing through the Strait of Hormuz is estimated at approximately 17-20 million barrels per day.
• Diplomacy — Following the collapse of the nuclear agreement (JCPOA), Iran has increased uranium enrichment to 60%, strengthening its negotiating leverage.
• Security — Iran has focused on developing asymmetric capabilities (fast attack craft, mines, anti-ship missiles, drones) to enhance its ability to blockade the strait.
• International Relations — Gulf states (such as Saudi Arabia, UAE, and Qatar) face the risk of being drawn into the escalating US-Iran conflict.
• Energy Markets — As the crisis deepens, crude oil prices are under upward pressure, with Brent crude approaching the high $90s per barrel.
• Military Strategy — Iran's explicit targeting of power plants across the Middle East for retaliation has highlighted the infrastructure vulnerabilities of Gulf states.
• Diplomacy — China and Russia maintain relations with Iran while officially calling for a resolution through dialogue.

The US-Iran conflict over the Strait of Hormuz is an extension of a structural rivalry spanning nearly half a century, dating back to the 1979 Iranian Revolution. However, to understand "why this crisis is happening now" in March 2026, it is necessary to overlay multiple historical contexts.

First, there is the collapse of the nuclear agreement (JCPOA) and the failure of its reconstruction. The Iran nuclear deal, concluded under the Obama administration in 2015, was a groundbreaking framework that lifted economic sanctions in exchange for limiting Iran's nuclear development. However, in 2018, the first Trump administration unilaterally withdrew from the JCPOA and initiated a "maximum pressure" policy. The Biden administration sought to rejoin the agreement, but negotiations stalled due to Iran's progress in uranium enrichment and the impact of the Russia-Ukraine war. The second Trump administration has adopted an even more hardline stance, and diplomatic channels have effectively remained closed. With the loss of the nuclear agreement as a "safety valve," relations between the two countries have fallen into a structure lacking a brake on military escalation.

Second, there is the maturation of Iran's asymmetric strategy. Although Iran is overwhelmingly inferior to the US military in conventional forces, it has refined its "anti-access/area denial (A2/AD)" strategy over the past two decades. The Islamic Revolutionary Guard Corps (IRGC) has systematically developed fast attack craft, mine-laying capabilities, anti-ship ballistic missiles, long-range cruise missiles, and, in recent years, suicide drones. The 2019 attack on Saudi Aramco oil facilities (attributed to the Houthis, but with Iranian technical support noted) and the large-scale missile and drone attack on Israel in April 2024 demonstrated Iran's actual capability for widespread retaliation. Iran's explicit statement of "retaliation against power plants supplying electricity to US military bases" is an extension of this asymmetric strategy, possessing the strategic rationale of indirectly paralyzing US military operational capabilities while avoiding direct military conflict.

Third, there is the issue of the Trump administration's diplomatic style. The "48-hour ultimatum" approach is part of the "brinkmanship" characteristic of Trump's diplomacy, seen in statements like "fire and fury" during the 2017 North Korea crisis and the assassination of General Soleimani in 2020. While this strategy exerts maximum psychological pressure on the adversary, it also carries the risk of narrowing the "exit" from escalation. Setting a 48-hour deadline severely limits room for negotiation and would cause Iran to lose face, making concessions domestically almost impossible for Iran. In other words, the ultimatum itself has a structure that escalates the conflict.

Fourth, there is the context of geopolitical realignment in the Middle East. Following the Abraham Accords (2020), normalization of relations between Israel and Gulf Arab states has progressed, deepening Iran's regional isolation. Meanwhile, China's mediation of diplomatic normalization between Saudi Arabia and Iran in 2023, among other developments, indicates that US unipolar dominance in the Middle East is wavering. For Iran, control over the strait is its single greatest leverage in this changing geopolitical landscape and cannot be easily relinquished.

Fifth, there are structural changes in the energy market. The US has increased its energy self-sufficiency through the shale revolution, reducing its direct dependence on Middle Eastern crude oil. However, China, now the world's largest crude oil importer, along with other East Asian countries like India, Japan, and South Korea, remain highly dependent on the Strait of Hormuz. This creates a paradoxical structure where a crisis in the Strait of Hormuz would deal a greater blow to US allies and strategic competitors rather than to the US itself. This asymmetry complicates the Trump administration's calculations.

These structural factors converge, and the March 2026 crisis should be understood not merely as an accidental escalation, but as the result of long-accumulated contradictions reaching a critical point. The absence of diplomatic safety valves, the maturation of asymmetric capabilities, the limits of brinkmanship, the fluidity of regional order, and the asymmetry of energy dependence structures—these structural conditions acting simultaneously are self-reinforcing the "spiral of conflict."

The delta: The "48-hour ultimatum" by the Trump administration marked a qualitative shift from the traditional sanctions and pressure approach to a direct military attack warning. Iran's explicit statement of infrastructure retaliation has created a risk that the scope of the conflict could expand from military clashes between the two countries to energy infrastructure across the entire Middle East. This signifies that the "spiral of conflict" has entered a new phase.