Both Sides of Hormuz Are Now Blocked and Neither Will Blink First

DUBAI — Only five ships transited the Strait of Hormuz in the 24 hours ending April 24, according to vessel-tracking data compiled by Kpler — one of them an Iranian-sanctioned oil products tanker — as the compounding effects of a US naval blockade and Iran’s own maritime enforcement reduced traffic through the world’s most important energy chokepoint to 3.6 percent of its pre-war baseline.

The near-total shutdown, which Bloomberg on Saturday characterized as a “double blockade,” has persisted despite a ceasefire nominally in effect since April 8 and despite Iran’s foreign ministry declaring the strait “completely open to commercial shipping” on April 24. Before the war began on February 28, between 100 and 140 vessels passed through Hormuz daily, carrying roughly 20 percent of the world’s oil supply. The International Energy Agency’s executive director, Fatih Birol, told CNBC on April 23 that the disruption now amounts to 13 million barrels per day offline — “more than the two 1970s oil crises combined.”

How the Double Blockade Works

The mechanism is straightforward in principle and nearly impossible to unwind in practice. Since March 4, when the IRGC Navy declared “full authority” over Hormuz, Iran has controlled which vessels can exit the Persian Gulf into the Gulf of Oman. Since April 13, when US Central Command declared it would blockade “the entirety of the Iranian coastline,” the US Navy has controlled which ships can enter from the Arabian Sea side.

A commercial vessel now needs approval from both militaries to complete a transit. Neither blockade has been lifted. CNBC reported on April 23 that rival militaries effectively control entry and exit points, creating what amounts to a structural deadlock with no single point of release.

The US blockade’s scope was narrowed within 14 hours of its announcement. President Trump’s initial Truth Social post on April 13 threatened “any and all Ships” transiting the strait. CENTCOM’s formal press release, issued at 10 a.m. ET the same day, specified the blockade applied to ships entering or departing Iranian ports — not all Hormuz traffic. Todd Huntley of Georgetown University Law Center wrote in Lawfare that “a total blockade of all maritime traffic through the Strait of Hormuz would violate international law.” The port-focused framing, as Frank G. Hoffman of the Foreign Policy Research Institute noted, “appears better suited to satisfy international law.”

But the operational effect has been broader than the legal framing suggests. Since the ceasefire on April 8, only 45 ships total have entered or exited the strait, according to Kpler data cited by Al Jazeera and Al-Monitor on April 24.

What Ghalibaf Conditioned — and What He Cannot Deliver

Iran’s parliament speaker, Mohammad Bagher Ghalibaf, posted on X on April 22 what amounted to the first formal public linkage of Hormuz reopening to US blockade removal. “A complete ceasefire only has meaning when it is not violated by a naval blockade and the holding hostage of the global economy, and if the Zionist warmongering across all fronts is halted,” he wrote. “Reopening the Strait of Hormuz is not possible under a blatant breach of the ceasefire.”

The statement was carried by France 24 and Voice of Emirates. Four days earlier, on April 18, Ghalibaf had been blunter: “It is impossible for others to pass through the Strait of Hormuz while we cannot.”

The linkage creates a policy trap. The US maintains the blockade because Iran closed the strait. Iran now formally conditions reopening on the blockade’s removal. Each side’s instrument gives the other a domestic justification to maintain its own.

But Ghalibaf’s statement is political, not operational. He is parliament speaker — a former IRGC Aerospace Force commander (1997–2000), fluent in the language of military escalation, but with no authority over IRGC Navy operations. The IRGC Navy reports to the Supreme Leader under Article 110 of Iran’s constitution, not to the Majlis. Khamenei has not been seen publicly for more than 50 days. President Pezeshkian publicly accused IRGC-aligned former Defense Minister Vahidi and Khatam al-Anbiya commander Abdollahi on April 4 of wrecking ceasefire efforts — an admission that the civilian government cannot command the IRGC to stand down.

The Institute for the Study of War reported on April 19 that “the IRGC appears to be controlling Iranian decision-making instead of Iranian political officials who are engaging with the United States in negotiations.” Ghalibaf’s statement aligns with IRGC demands but does not bind IRGC operations. It is political institutionalization of the closure, not an operational command.

Enforcement by the Numbers

On the US side, CENTCOM has deployed at least 27 Navy vessels — roughly 41 percent of all actively deployed US warships worldwide — including three carrier strike groups led by the USS Abraham Lincoln and the USS George H.W. Bush, with a third en route. Stars and Stripes reported on April 14 that the force includes 16,500 sailors and Marines, with named destroyers USS Mason, USS Ross, USS Donald Cook, and USS Spruance, mine countermeasures vessels USS Chief and USS Pioneer, Boeing P-8 Poseidon maritime patrol aircraft, and the 31st Marine Expeditionary Unit.

Through April 24, CENTCOM had turned around 31 Iranian-linked vessels. The first seizure came on April 19, when the USS Spruance disabled the engine of the Iranian-flagged MV Touska with 5-inch gunfire. Two VLCCs followed: the Tifani on April 21 and the Majestic X on April 23, each carrying approximately 1.9 million barrels. Lloyd’s List reported that at least 26 Iranian vessels had evaded the blockade by April 20.

On Iran’s side, the IRGC Navy operates approximately 50,000 personnel across five Gulf sectors, with 38 controlled islands and more than 10 fortified bases, according to Asharq Al-Awsat. The fleet includes over 100 fast-attack craft, mine-laying boats, drone platforms, the Shahid Bagheri drone carrier (a converted container ship), and miniature submarines.

Michael B. Petersen, a non-resident senior fellow at FPRI, described the US approach as “a ‘distant (or semi-distant)’ blockade of vessels that have paid a toll to Iran,” adding that “this approach requires significant assistance from allies and partners to be fully successful.” That assistance has not materialized. Unlike the 1987–88 Tanker War, when NATO allies provided mine countermeasures support, no allied nation has committed naval assets to the 2026 operation.

Why Did Iran’s “Open” Declaration Change Nothing?

On April 24, Iran’s foreign ministry declared the Strait of Hormuz “completely open to commercial shipping.” Bloomberg’s vessel-tracking data the following day showed two small Iranian fuel carriers and one coastal cargo ship transiting — functionally indistinguishable from zero commercial traffic.

The declaration failed for two reasons, one on each side of the strait. On the Iranian side, the IRGC had seized the MSC Francesca (11,660 TEU, Liberia-flagged) and the Epaminodas (6,690 TEU, Panama-flagged) on April 22 — two days before the “open” announcement. The IRGC claimed the ships “had endangered maritime security by operating without the required authorization and by tampering with navigation systems.” UKMTO reporting contradicted this, indicating both vessels had received Iranian passage clearance before being seized.

Jakob Larsen, chief safety and security officer at BIMCO, told The National on April 24: “The fact that ships were attacked following apparent Iranian approval to transit underscores the complexity and volatility of the security situation.” He added that “for most shipping companies, they will need a stable ceasefire and assurances from both sides.”

On the US side, Defense Secretary Pete Hegseth announced on April 23–24 that the blockade would last “as long as it takes,” with a single condition: that Iran “abandon a nuclear weapon in meaningful and verifiable ways, or instead they can watch the regime’s fragile economic state collapse.” He added: “Our blockade is growing and going global.” On April 24, Trump ordered Navy personnel to shoot and kill Iranian mine-laying crews in the strait.

Peter Sand, chief analyst at Xeneta, said on April 24: “The latest seizures make clear, even an ‘open’ Strait of Hormuz is not a safe Strait of Hormuz for seafarers, ships and cargo.”

Iran’s Parliament Moves to Legislate the Closure

While Ghalibaf made his demands publicly, Iran’s parliamentary National Security and Foreign Policy Committee was advancing a 12-article bill titled “Law on Establishing Iran’s Sovereignty over the Strait of Hormuz.” The bill, reported by PressTV on April 21 and confirmed by GlobalSecurity, would ban vessels from “hostile countries” from transiting without Supreme National Security Council approval, prohibit all Israeli-linked cargo, impose rial-denominated tolls, authorize confiscation of 20 percent of cargo from non-compliant vessels, and extend the transit ban to states that do not use “Persian Gulf” in official documents.

Named lawmakers behind the bill include Vahid Ahmadi and Mohammad Reza Rezayi Kouchi. The legislation would codify what the IRGC has imposed by force since March 4 — transforming an emergency military posture into permanent statute.

This is the same dynamic that rendered Foreign Minister Araghchi’s earlier Hormuz declarations meaningless. The civilian government can announce openings. The IRGC can seize ships the same day. And parliament can legislate the closure into law while the foreign ministry promises the opposite.

Can the Strait Be Cleared Even If Both Sides Stand Down?

Even in a scenario where both blockades are simultaneously lifted, the strait would not reopen immediately. The Pentagon told the House Armed Services Committee that clearing Iranian mines from Hormuz could take up to six months after any peace deal is reached. Iran began planting mines around March 10, and more than 20 GPS-guided devices have been reported, according to Pentagon briefings. Iran has acknowledged losing track of some of its own mines.

The US mine countermeasures capability in the region has degraded. Four Avenger-class MCM ships were decommissioned at their Bahrain homeport in September 2025. Only USS Chief and USS Pioneer remain in theater — two ships to clear a waterway where the 1991 Kuwait mine clearance operation, covering roughly 200 square miles, required four Avengers.

The command vacuum within the IRGC Navy compounds the problem. Commander Alireza Tangsiri was killed on March 30. No named successor has been announced. The force that laid the mines has no identified commanding officer, raising questions about who could provide mine charts or coordinate clearance in any future agreement.

Market Fallout and the Yanbu Ceiling

The mutual blockade has exposed the limits of Saudi Arabia’s East-West Pipeline bypass. Bloomberg reported on April 24 that actual loadings at Yanbu were running at approximately 4 million barrels per day against a port ceiling of 5.9 million bpd and a pipeline capacity of 7 million bpd. Pre-war Saudi exports through Hormuz totaled 7 to 7.5 million bpd, leaving a structural shortfall of 1.1 to 1.6 million bpd that no bypass can close.

Matt Wright, principal freight analyst at Kpler, told The National on April 24 that “it’s the re-entries that are the real test of what’s going on” — meaning the market is watching not for declarations of openness but for actual inbound vessel traffic.

Jared Cohen, co-head of the Goldman Sachs Global Institute, told Fortune on April 25 that even in a best case, “you may have traffic flowing through, but the Iranians will likely maintain partial or unilateral control.” He characterized the current situation as “sloppy peace” — “a bunch of half solutions on all the big issues.”

War-risk insurance premiums have surged several-fold since February 28, according to BIMCO. Xeneta’s recovery projections assume unhindered passage — conditions that do not exist. Tankers and dry bulk may reach full recovery by July; container ships roughly 50 percent by July, normalizing in August; LNG carriers not until September.

Kenneth Katzman, a former Congressional Research Service analyst, told Al Jazeera on April 24 that Iran has 160 to 170 million barrels of crude in floating storage — enough to maintain revenue flows until approximately August. Trump “probably won’t” maintain the blockade that long, Katzman said. Adam Ereli, a former US ambassador to Bahrain, told the same outlet that Iran “can tolerate pain for a lot longer than most American decision makers calculate.”

“There is no safe and free passage through the Strait of Hormuz. This is the weaponization of trade, with both sides recognizing the pain they can inflict.”Peter Sand, Chief Analyst, Xeneta, April 22

Background

The current Hormuz crisis is the most severe since the 1987–88 Tanker War, when Iraq carried out 283 attacks on shipping and Iran 168, killing 116 merchant sailors. The USS Samuel B. Roberts struck an Iranian mine on April 14, 1988, triggering Operation Praying Mantis — the US Navy’s largest surface engagement since World War II. During that conflict, NATO allies provided mine countermeasures and escort support; no equivalent coalition has formed in 2026.

The sequence that produced the double blockade unfolded in stages: the IRGC declared “full authority” over Hormuz on March 4; the US imposed its Iranian port blockade on April 13; the IRGC cited the US blockade as justification for continued closure on April 17–18; Ghalibaf formalized the linkage on April 22; Iran’s parliament advanced sovereignty legislation on April 21; the IRGC seized the MSC Francesca while the strait was supposedly “open” on April 22; Trump ordered shoot-to-kill on April 24; and Hegseth declared “as long as it takes” the same day.

Max Boot, the Jeane J. Kirkpatrick Senior Fellow at the Council on Foreign Relations, published an “Open for Open” analysis arguing that the mutual-trap logic means “neither one will lose face by opening it — as long as the other one does the same.” The problem, Frederic Schneider of the Middle East Council on Global Affairs told Al Jazeera, is that Trump faces a May 1 congressional deadline on the blockade while Iran is playing “the longer game.”

FAQ

How does the US blockade differ legally from Iran’s closure?

The US blockade is port-targeted — it applies only to ships entering or departing Iranian ports, giving it defensible standing under international law. Iran’s approach has none: UNCLOS Articles 38–44 guarantee transit passage through international straits for vessels of all nations regardless of origin or destination, and no provision allows a coastal state to require advance IRGC authorization as a condition of transit. Both operations inflict equivalent economic damage, but the US has constructed a narrower legal exposure.

What would a simultaneous withdrawal look like operationally?

A stand-down agreement would not reopen the strait on day one. The Pentagon estimates mine clearance alone could take up to six months — and that assumes full cooperation including Iranian mine charts. With only two MCM vessels in theater (USS Chief and USS Pioneer) and no allied mine clearance commitments, the timeline could extend further. Insurance underwriters would need to see sustained safe passage before reducing war-risk premiums, and shipping companies would require what BIMCO’s Larsen calls “a stable ceasefire and assurances from both sides” before routing vessels back through the strait.

How long can Iran sustain revenue under the blockade?

Katzman estimates Iran’s 160–170 million barrels in floating storage could sustain revenue flows until roughly August 2026. Schneider noted that Iran also has crude oil reserves in onshore floating-roof tanks. But the blockade’s economic damage extends beyond oil exports. Iran’s Central Bank has circulated an internal memo projecting 180 percent inflation and a 12-year recovery timeline if the crisis persists, according to reporting by Iranian media in April. The parliament’s proposed rial-denominated toll system has collected zero revenue in 36 days of operation.

Why hasn’t Saudi Arabia’s Yanbu bypass fully compensated for the Hormuz closure?

Three constraints compound. The East-West Pipeline’s port loading ceiling (5.9 million bpd) is below pre-war Hormuz export volumes (7–7.5 million bpd), leaving a minimum 1.1 million bpd gap even at full capacity. Actual loadings are well below the ceiling — partly because Saudi production has fallen sharply since the war began, reducing the volume available to route through either corridor. And the bypass does nothing for non-Saudi Gulf producers — Kuwait, Iraq, and UAE crude has no Red Sea alternative, leaving most of the strait’s pre-war throughput entirely blocked. Iran is now extending this architecture to a second chokepoint, with Houthi toll mechanisms for Bab el-Mandeb reportedly designed with Iranian involvement — potentially closing Saudi Arabia’s only remaining export corridor to Asia as well.

What is the significance of Iran’s 12-article sovereignty bill?

The bill would transform the IRGC’s emergency military posture into permanent Iranian law, making any future reopening contingent on legislative repeal rather than a military stand-down order. It would also establish legal grounds for cargo confiscation (20 percent of non-compliant shipments), rial-denominated tolls, and a ban on vessels from states that do not use “Persian Gulf” in official documents — a provision that would technically bar ships flagged in several Arab states. If enacted, it would make Hormuz closure the legal default rather than an exceptional wartime measure.