Iran Fires on Ships in Strait of Hormuz as US Deploys Additional Forces to Middle East

Iran's Islamic Revolutionary Guard Corps fired on three commercial vessels and seized two others in the Strait of Hormuz on April 22, 2026, in the most aggressive Iranian maritime action since the current conflict began. The attacks came hours after President Donald Trump indefinitely extended a ceasefire that Iran's own negotiating team had already dismissed as irrelevant [1][2][3].

The incidents threaten to unravel what remains of a fragile diplomatic process brokered through Pakistan, while raising the stakes for global energy markets: roughly 34% of the world's seaborne crude oil and 20% of its liquefied natural gas pass through the narrow waterway Iran now claims the right to control [4][5].

What Happened in the Strait

The United Kingdom Maritime Trade Operations (UKMTO) documented the first attack on Wednesday morning: an IRGC gunboat approached a Liberian-flagged container vessel without radio warning and opened fire, causing "heavy damage to the bridge" [3][6]. No crew members were injured. A second cargo vessel was also targeted, though UKMTO reported no damage or casualties from that incident [7].

Hours later, the IRGC announced it had seized two additional vessels — the MSC Francesca and the Epaminondas — along with a third ship called the Euphoria, and transferred them to Iranian shores [8][9]. The Guards claimed the ships were "operating without proper authorization, repeatedly violating regulations, and manipulating navigation systems" [8]. A Greek-owned vessel was also reportedly disabled off Iran's coast [6].

The private security firm Vanguard Tech contradicted Tehran's account, confirming that the first vessel fired upon had permission to transit the strait [3]. The IRGC's stated justification — that "any passage of ships, vessels or oil tankers through the Strait of Hormuz should be with the permission and coordination of the IRGC" — amounts to a unilateral claim of authority over an international waterway [3].

Escalation Beyond Past Patterns

Iran has a long history of seizing commercial vessels in the strait. Between 2019 and 2023, the IRGC seized or harassed at least 20 tankers and cargo ships, including the British-flagged Stena Impero in 2019 and multiple oil tankers in 2023 [10]. But Wednesday's events mark a qualitative escalation: Iran fired live rounds at commercial ships, moved from seizing individual tankers to targeting multiple vessels simultaneously, and did so while a ceasefire was nominally in effect.

The context also differs. Past seizures were largely tit-for-tat responses to specific incidents — a detained Iranian tanker near Gibraltar, a sanctions enforcement action. Wednesday's attacks occurred against the backdrop of a declared war, a US naval blockade, and the collapse of peace negotiations [2][11].

The Ceasefire That Isn't

President Trump extended the two-week ceasefire on April 21, one day before it was set to expire. He said the extension was warranted because Iran's government was "seriously fractured" and would continue "until such time as" Tehran submits a "unified proposal" to end the war [12][13].

Trump said he acted at the request of Pakistani Prime Minister Shehbaz Sharif and Pakistan's Field Marshal Asim Munir, who had been mediating indirect talks between Washington and Tehran in Islamabad [12][14]. Vice President JD Vance had been scheduled to fly to Pakistan for a second round of negotiations, with Air Force Two already positioned at Joint Base Andrews, but the trip was called off after Trump's announcement [12].

Iran rejected the extension outright. Mahdi Mohammadi, an adviser to Iran's chief negotiator, said: "Trump's ceasefire extension means nothing, the losing side cannot dictate terms" [7]. Iranian Foreign Minister Seyed Abbas Araghchi has called the US naval blockade "an act of war and thus a violation of the ceasefire," insisting that it must be lifted before any talks can resume [2][11].

The core stalemate is straightforward: Iran demands the US end its blockade of Iranian ports as a precondition for negotiations. Trump has refused, saying "We're not going to open the strait until we have a final deal" [15]. Each side views the other's position as a violation of the ceasefire itself.

The Energy Chokepoint

The Strait of Hormuz, at its narrowest just 21 miles wide, remains the world's most consequential energy bottleneck. Nearly 15 million barrels per day of crude oil — about 34% of global seaborne crude trade — transit the waterway. Another 20% of global LNG trade, primarily from Qatar, passes through the same corridor [4][5].

Source: EIA / IEA

Data as of Apr 22, 2026CSV

The destination of these flows matters for understanding who bears the risk. Almost 90% of the oil exported through the strait goes to Asian markets, with China and India receiving 44% of the total. Europe takes just over 10% of crude volumes, though it depends on the strait for roughly 7% of its LNG imports [4]. A sustained Iranian interdiction campaign — even targeting a fraction of shipping — would create immediate price spikes in Asian spot markets, with cascading effects on European gas markets within weeks.

Oil prices rose on Wednesday following news of the attacks [6]. War-risk insurance premiums have already transformed the strait into the world's most expensive commercial waterway, with rates surging over 300% compared to January 2025 levels [16][17].

Source: S&P Global / Euronews

Data as of Apr 22, 2026CSV

Before the crisis, war-risk insurance for a vessel transiting the Gulf ran 0.02% to 0.05% of the ship's hull value. After the February 2026 US-Israeli airstrikes on Iran, premiums jumped to 0.5% to 1%. A very large crude carrier (VLCC) that once paid roughly $100,000 for transit coverage now pays over $400,000 [16]. Major carriers including Maersk, MSC, CMA CGM, and Hapag-Lloyd have suspended voyages through the Gulf entirely [16][17].

The US Military Buildup

The Pentagon is deploying more than 10,000 additional military personnel to the Middle East, the largest US force movement to the region since the 2003 Iraq invasion [18][19][20].

The deployment consists of two main elements. The USS George H.W. Bush Carrier Strike Group, carrying approximately 6,000 personnel, departed Naval Station Norfolk in late March [18]. The Boxer Amphibious Ready Group and its embarked 11th Marine Expeditionary Unit, with roughly 4,200 troops, are expected to arrive by month's end [18][19].

These reinforcements join forces already in the region: the USS Abraham Lincoln carrier strike group with three destroyers, at least 2,500 Marines and sailors aboard the USS Tripoli, and elements of the 82nd Airborne Division [21][22]. The combined presence represents one of the largest US military concentrations in the Middle East since the pre-war period.

Treasury Secretary Scott Bessent confirmed the Navy maintains its blockade of Iranian ports, targeting Iran's oil revenue as an economic pressure tool alongside the military buildup [7].

Legal Claims and Counterclaims

Iran's legal position rests on a deliberate rejection of modern maritime law. Tehran has never ratified the United Nations Convention on the Law of the Sea (UNCLOS), which established the principle of "transit passage" — the right of all ships to pass through international straits without coastal state interference, provided the transit is "continuous and expeditious" [23][24].

Instead, Iran cites pre-UNCLOS law, particularly the International Court of Justice's 1949 Corfu Channel ruling and the 1958 Territorial Seas Convention, which establish the more restrictive standard of "innocent passage." Under this framework, Iran claims broad discretion to regulate — and suspend — shipping through its territorial waters in the strait [23][24][25].

Iran's 1993 Marine Areas Act extends Iranian sovereignty to a 12-nautical-mile territorial sea and claims control over strategically significant islands including Qeshm, Hormuz, Larak, and the disputed Abu Musa and Greater and Lesser Tunb islands [24]. Iran has maintained a "persistent objector" position to transit passage rules since the UNCLOS negotiations of the 1970s [24][25].

Legal scholars are divided. James Kraska, a maritime law professor, characterizes Iran's position as "lawfare" and argues Tehran must "abide by the compromises made in UNCLOS" [25]. But other specialists note that only six countries globally support the US interpretation of transit passage as customary international law binding on non-signatories — making Washington's position an outlier as well [25]. The 1958 convention Iran cites explicitly prohibits suspending innocent passage through international straits, undermining Tehran's own legal argument [24].

The US position has its own complications. Washington has not ratified UNCLOS either, but argues its transit passage provisions reflect customary international law. The US naval blockade of Iranian ports itself raises questions under international law, as blockades are traditionally considered acts of war [2][11].

Who Pays the Price

The commercial toll extends well beyond the ships directly targeted. The London insurance market has seen marine war coverage for the Hormuz region effectively dry up, with some underwriters refusing to write new policies altogether [16][17]. Lloyd's of London's market association has noted that "safety concerns, not insurance availability" are driving reduced vessel traffic — a distinction that may be technically accurate but functionally irrelevant to shippers who cannot secure coverage at any price [26].

The shipowners directly affected represent a cross-section of global maritime commerce. The MSC Francesca belongs to Mediterranean Shipping Company, the world's largest container shipping line, headquartered in Geneva. The seizure of vessels flying various flags — Liberian registration is a common flag of convenience — complicates the diplomatic response, as flag states, beneficial owners, and crew nationalities often span multiple countries [3][8].

The EU's foreign policy chief Kaja Kallas criticized "daily U-turns" over strait access, while China warned of the "critical stage" of the situation [7]. UN Secretary-General António Guterres cautiously welcomed the ceasefire extension [7].

Deterrence or Provocation?

The question of whether the US military buildup deters Iranian aggression or provokes it has no clean answer, and the evidence supports both readings.

Proponents of the deployment point to the June 2025 twelve-day war, which "confounded" widespread predictions that a US attack on Iran would "prompt massive retaliation, lead to thousands of American casualties, and spark an 'all-out' regional war" [27]. The conflict, focused on Iranian nuclear facilities, ended relatively quickly, suggesting that credible force can constrain Iranian responses.

Critics counter that Wednesday's ship attacks occurred against a backdrop of maximum US military presence in the region — raising the question of what, precisely, the 10,000 additional troops are deterring. The Washington Institute for Near East Policy has acknowledged that enhanced US posture "increases deterrence, but it also raises the risk of misinterpretation, as Iran may view these deployments as preparatory steps for a preemptive strike rather than defensive positioning" [27].

Gulf News described the Trump administration's strategy as "deterrence and restraint" — maintaining overwhelming force while avoiding direct engagement [28]. But Iran's IRGC has historically operated on its own escalatory logic, using asymmetric tactics precisely when conventional military pressure is highest. The seizure and firing on ships while a ceasefire is nominally in effect fits this pattern.

Iran's Economic Crisis and Domestic Calculations

Iran's economy provides critical context for understanding Tehran's risk calculus. Inflation reached 62.2% year-over-year in February 2026, with food prices rising at a historical high of 99% annually [29][30]. The Iranian rial has collapsed, falling from approximately 42,000 to over 1.1 million against the US dollar [30].

Source: World Bank / Fortune

Data as of Apr 22, 2026CSV

Nationwide protests erupted on December 28, 2025, driven by the economic crisis, currency depreciation, and shortages linked to sanctions and government mismanagement [31]. Factories, energy facilities, bridges, and railways destroyed in the June 2025 war have left many Iranians unemployed, though the government has not published reliable figures [29].

Iran's oil exports, estimated at roughly $30 billion annually in 2025, remain its economic lifeline — but the country loses approximately 20% of potential revenue to sanctions-evasion discounts, even as it continues shipping primarily to China [30][32].

The domestic political picture is fractured along familiar lines. The Islamic Revolutionary Guard Corps, which processes roughly half of Iran's oil exports and has collected tolls from Strait of Hormuz shipping, benefits materially from continued confrontation — its economic interests are directly threatened by a US blockade, giving it institutional incentives to escalate [29]. Parliament speaker and lead negotiator Mohammad-Bagher Ghalibaf has faced accusations of "betrayal" and even hints of a "coup" from hardline critics for engaging in indirect talks with Washington [33].

Pragmatists within the regime argue that Iran cannot endure indefinite isolation, viewing sanctions relief and reintegration into the international order as necessary for state survival [33]. But the war and blockade have strengthened hardline factions who frame any negotiation as capitulation — a dynamic that the ceasefire extension, with its requirement for a "unified proposal," may inadvertently exacerbate by forcing Iran's fractured leadership to produce consensus under pressure [12][33].

What Comes Next

The situation as of April 22 is one of simultaneous escalation and diplomatic paralysis. Iran is firing on commercial ships while rejecting a ceasefire it considers illegitimate. The United States is extending that ceasefire while maintaining a blockade that Iran considers an act of war. Pakistan's mediation effort, which produced the only direct channel between Washington and Tehran, is on hold [2][7][12].

The immediate variables to watch are whether the ship attacks provoke a US military response — which would effectively end the ceasefire regardless of its formal status — and whether insurance market dynamics force a de facto closure of the strait to commercial traffic even without a formal Iranian blockade. The distinction between a waterway that is legally open and one that is commercially uninsurable may prove academic.

The broader question is whether either side has an off-ramp. Trump has tied the blockade's removal to a "final deal." Iran has tied negotiations to the blockade's removal. Without a third-party mechanism to break this circular deadlock — and with hardliners on both sides benefiting politically from confrontation — the gap between ceasefire and conflict continues to narrow.