Key Points and Summary: Following recent US strikes on its nuclear facilities, Iran has threatened to close the Strait of Hormuz, a critical chokepoint for about 20% of global petroleum consumption. While Iran’s parliament has reportedly approved a measure to do so, experts believe a full, sustained closure is unlikely.
-Iran possesses the asymmetric capabilities to disrupt traffic using naval mines, fast attack craft, and anti-ship missiles, which would cause oil prices to spike dramatically.
-However, such an action would be “economic suicide” for Iran itself, alienate key partners like China, and almost certainly provoke a swift and overwhelming international military response led by the US Navy’s Fifth Fleet.
Would Iran Dare Close the Strait of Hormuz?
With tensions between the U.S. and Iran heating up to historical highs, all eyes are on Iran to see how it will respond to the U.S.’ attack against its nuclear sites.
Iran has threatened to take several measures in retaliation, from bombing American bases in Iraq (which seems to have happened already) to closing the Strait of Hormuz.
Iran currently fields a moderately small but deadly navy that could utilize several tactics to close or significantly reduce naval traffic through the Strait of Hormuz.
Could Iran Close the Strait of Hormuz?
Iran has long maintained a military presence in the region and possesses a range of capabilities that could be used to disrupt traffic in the strait.
These include fast attack boats operated by the Islamic Revolutionary Guard Corps (IRGC), anti-ship missiles, naval mines, submarines, drones, and coastal defense systems.
While these assets could be used to harass or temporarily block shipping lanes, sustaining a complete blockade would be extremely difficult, especially in the face of an international military response.
Mining the Strait of Hormuz would likely be one of Iran’s most effective tactics if it wanted to pursue such a strategy. In the Iran-Iraq War, Iran used a similar strategy to significant effect, significantly impeding Iraqi naval maneuvers. Mining the Hormuz Strait would significantly hamper military and civilian passage through the area.
Furthermore, the use of marine UAVs could also hinder naval passage in a strategy similar to that used by Ukraine in the Black Sea.
These asymmetric tactics would pose an even greater challenge to the U.S. and its allies.
Again, keeping the Strait closed for an extended time would be difficult, but Iran poses enough of a threat that commercial ships would be forced to reroute for their own safety.
Implications of Closing the Strait of Hormuz
As of June 2025, tensions have escalated following U.S. airstrikes on Iranian nuclear facilities. In response, Iran’s parliament approved a measure to close the Strait of Hormuz. However, the final decision rests with Iran’s Supreme National Security Council.
Despite this legislative move, most experts believe the likelihood of an actual closure remains low due to the severe economic and diplomatic consequences Iran would face.
From a legal standpoint, the Strait of Hormuz is considered an international strait under the United Nations Convention on the Law of the Sea (UNCLOS). This designation grants all nations the right of transit passage, which cannot be impeded by coastal states, including Iran.
Although Iran is not a signatory to UNCLOS, the principles of customary international law still apply. Therefore, any attempt to blockade the strait would be considered illegal under international law unless it occurred during a formally declared war and was recognized under the laws of armed conflict.
A Bad Idea for Iran
For Iran, the economic consequences of closing the Strait would be severe. The country exports a significant portion of its own oil through the strait, and blocking it would damage its own economy. Additionally, such a move would likely alienate key allies and trading partners, including China, which relies heavily on Gulf oil.
A blockade would also provoke a military response from the United States and its allies.
The U.S. Navy’s Fifth Fleet, based in Bahrain, is tasked with ensuring freedom of navigation in the region and would likely act swiftly to reopen the strait.
The global consequences of a blockade would also be significant. Oil prices would likely spike dramatically, potentially triggering global inflation. Shipping disruptions would increase insurance premiums for tankers, and rerouting oil shipments would be logistically complex and costly.
A blockade could also escalate into a broader regional conflict involving Gulf states, the United States, and possibly Israel.
Closing the Strait Would Not Benefit Iran
This is not the first time Iran has threatened to close the Strait of Hormuz. Iran has repeatedly threatened to close the Strait during periods of heightened tension with the United States and its allies. However, it has never followed through on these threats.
For example, during the 2011–2012 standoff over Iran’s nuclear program, similar threats were made. The United States responded by increasing its naval presence in the region, and Iran ultimately backed down. These threats are often seen as strategic posturing rather than actionable policy.
If the strait were blocked, some oil could be rerouted through alternative pipelines. Saudi Arabia’s East-West Pipeline connects the Persian Gulf to the Red Sea, bypassing the strait. The United Arab Emirates also has the Habshan-Fujairah pipeline, which serves a similar purpose.
However, these alternatives have limited capacity and cannot fully compensate for the volume that normally passes through the Strait of Hormuz.
Despite its military capabilities and history of threats, Iran has more to lose than gain from closing the Strait. Such a move would provoke a military response that could damage Iran’s infrastructure and threaten regime stability.
It would also isolate Iran diplomatically, even among sympathetic nations, and further damage its already strained economy. When rating the likelihood of Iran actually closing the Strait of Hormuz, experts almost universally agree that the IRGC is unlikely to pursue such actions.
About the Author:
Isaac Seitz, a Defense Columnist, graduated from Patrick Henry College’s Strategic Intelligence and National Security program. He has also studied Russian at Middlebury Language Schools and has worked as an intelligence Analyst in the private sector.
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