Following recent, unprecedented U.S. airstrikes on key Iranian nuclear facilities, Iran has vowed retaliation, with some voices within the country calling for the closure of the strategically vital Strait of Hormuz. This narrow waterway is one of the world’s most critical chokepoints for global energy shipments. However, despite the heightened tensions, experts widely believe that a full, sustained blockade of the Strait by Iran remains highly improbable.
The Context: US Strikes and Iran’s Immediate Reaction
Early on a Sunday, the U.S. significantly escalated its involvement in the Israel-Iran conflict by launching a massive air and naval assault against three prominent Iranian nuclear sites: Fordo, Natanz, and Isfahan. Dubbed “Operation Midnight Hammer,” the operation involved over 125 U.S. military aircraft, including B-2 stealth bombers which dropped 14 GBU-57 “bunker buster” bombs, and submarines launching Tomahawk cruise missiles. U.S. officials stated the goal was to “destroy or severely degrade” Iran’s nuclear program, not target its people or seek regime change, though President Donald Trump claimed the sites were “obliterated.”
Iran immediately condemned the action as an “unjust war of aggression” and a “grave violation” of international law, vowing retaliation. Iran’s parliament subsequently voted in support of closing the Strait of Hormuz as a potential response. While this parliamentary vote is advisory, informing the leadership of the option, the ultimate decision rests with Iran’s Supreme National Security Council and Supreme Leader Ayatollah Ali Khamenei. Iran has already launched missile barrages into Israel following the U.S. strikes, and allies like the Houthis in Yemen have pledged support, signaling Iran’s capacity and willingness for regional action beyond the Strait.
Why the Strait of Hormuz is Globally Critical
The Strait of Hormuz connects the Persian Gulf to the Gulf of Oman and the open sea, serving as the sole maritime passage for vast quantities of oil and gas produced in the Gulf region. Its importance cannot be overstated:
Oil: Approximately 30% of the world’s traded oil, amounting to around 21 million barrels per day of crude oil and products (a fifth of global supply), passes through the Strait daily. This includes exports from major producers like Saudi Arabia, Kuwait, Iraq, Iran, and the UAE.
Natural Gas: Around 20% of the global liquefied natural gas (LNG) trade, primarily from Qatar, transits the waterway.
LPG: One-third of the world’s liquefied petroleum gas (LPG) shipments also use the Strait.
In total, roughly 30 to 33 million barrels of oil equivalent per day navigate this narrow chokepoint. Any significant disruption would have immediate and severe repercussions for global energy markets, potentially causing oil prices to spike dramatically.
Can Iran Block the Strait? (Temporarily, Yes)
Iran certainly possesses the military capability to disrupt traffic in the Strait of Hormuz for a limited period. The Islamic Revolutionary Guard Corps (IRGC) Navy operates numerous fast-attack boats, anti-ship missiles positioned along Iran’s extensive coastline, and naval mines. These assets could be employed to harass or attack commercial shipping, potentially blocking the waterway or making it too dangerous to navigate. Historical instances exist, such as targeting tankers during the Iran-Iraq War, which didn’t achieve a full blockade but severely increased shipping insurance premiums and caused delays.
Why a Full, Sustained Blockade is Highly Unlikely
Despite the threats and the potential for temporary disruption, a comprehensive and prolonged closure of the Strait of Hormuz is widely considered unlikely due to several critical factors:
- Overwhelming U.S. Military Response: A move to shut down the Strait would be viewed by the United States and its allies as an act of war threatening global commerce. The U.S. Navy’s Fifth Fleet is headquartered nearby in Bahrain and its task forces routinely patrol the area. The U.S. possesses vastly superior naval and air power in the region and has “very good plans,” according to former U.S. Central Command head Retired Gen. Frank McKenzie, to clear the Strait if necessary. Any Iranian attempt at a full blockade would likely trigger an immediate, powerful response aimed at restoring navigation freedom and neutralizing Iran’s naval capabilities, leaving Iran’s own coastline highly vulnerable.
- Severe Economic Self-Harm: Blocking the Strait would deal a devastating blow to Iran’s own economy. Iran relies on the Strait for approximately 1.65 million barrels per day of its crude oil and gas condensate exports. The vast majority (around 90%) of these exports, often sold at a discount due to sanctions, go to China. Furthermore, over half of all energy exports passing through the Strait are ultimately destined for China, the world’s largest hydrocarbon importer. Closing the Strait would cut off Iran’s primary revenue stream and likely incur significant pressure from Beijing, Iran’s crucial political and economic partner. Secretary of State Marco Rubio described closing the Strait as “suicidal” for Iran, noting that the “whole world would come against them.”
- Existence of Alternative Export Routes: While not completely bypassing the Strait for all regional output, Saudi Arabia and the UAE, key energy exporters, have pipeline alternatives that could mitigate some of the impact of a closure. Saudi Arabia’s East-West pipeline has a potential capacity of 5.1 million barrels per day, loading from the Red Sea (though this route faces threats from Iran-backed Houthis). The UAE’s Abu Dhabi to Fujairah pipeline, with a 1.5 million barrels per day capacity, completely bypasses the Strait, terminating at a port on the Gulf of Oman capable of handling nearly 75% of the UAE’s total crude output. These pipelines mean a Strait closure would not knock all regional exports offline.
Other Potential Retaliation Routes
Experts note that Iran has developed a multi-tiered military capability, partly to deter attacks, and the U.S. strike might lead Iran to activate these options. While the Strait is a possibility, Iran could also retaliate through other means that might be less economically damaging to itself and less likely to provoke a full-scale U.S. invasion aimed at regime change:
Attacking U.S. Bases and Allies: Iran could target U.S. military personnel and infrastructure located on bases in nearby Gulf countries, which are closer than Israel.
Activating Regional Proxies: Iran might call upon allied militias in Iraq or the Houthis in Yemen to conduct drone or missile attacks against U.S. or allied interests, potentially resuming attacks on Red Sea shipping.
Accelerating the Nuclear Program: Although the full damage from the U.S. strikes is unknown, Iran could respond by ending cooperation with the IAEA, potentially withdrawing from the Nuclear Nonproliferation Treaty (NPT), and sprinting towards higher enrichment levels.
Conclusion: High Stakes, Calculated Risk
While the U.S. strikes have undeniably raised tensions to dangerous levels and Iran has openly discussed targeting the Strait of Hormuz, a full, sustained blockade appears to be a measure with consequences so severe and self-defeating for Iran that it remains highly unlikely. For years, Iran has threatened this action but has never fully executed it.
Although minor incidents, harassment of shipping, or even temporary disruptions cannot be ruled out, a complete closure that aims to halt global energy flow is a scenario that Iran’s leadership has historically avoided, likely recognizing that it would invite overwhelming military force and cripple their own economy. The current situation is fraught with risk, but the economic and military realities make a sustained Strait blockade a particularly unattractive option for Tehran compared to other potential forms of retaliation.
