Iran Can Only Partially Shut the Strait of Hormuz: That's Still a Huge Problem

As tensions escalate in the Middle East, Iran’s repeated threats to disrupt the Strait of Hormuz have once again thrust this critical maritime chokepoint into the global spotlight. While experts argue that Iran lacks the capacity to fully close the Strait, its ability to impede traffic through mines, missile attacks, and naval harassment could inflict significant economic damage worldwide. Amid recent U.S. and Israeli strikes on Iranian nuclear sites and Iran’s retaliatory missile barrage on Israel, the Strait remains a flashpoint where even partial disruption could roil energy markets and global trade.

The Strategic Importance of the Strait

The Strait of Hormuz, a narrow waterway between Iran and Oman, connects the Persian Gulf to the Gulf of Oman and the Arabian Sea. At its narrowest point, it spans just 21 miles, with two-mile-wide shipping lanes for inbound and outbound traffic separated by a two-mile buffer. According to the U.S. Energy Information Administration, about 20 million barrels of oil per day, roughly 20% of global oil consumption, pass through the Strait, alongside a third of the world’s liquefied natural gas. Major oil producers like Saudi Arabia, Kuwait, Iraq, and Iran rely on this route for exports, making it a vital artery for global energy markets.

Iran’s Capabilities: Disruption Over Closure

While Iran has threatened to “close” the Strait, analysts widely agree that a complete blockade is unlikely and unsustainable. “Let’s be real about the Strait of Hormuz. It’s wide enough that the Iranians cannot close it,” energy expert Anas Alhajji told CNBC. The U.S. Fifth Fleet, stationed in Bahrain, and allied naval forces would likely counter any attempt swiftly, and Iran’s own oil exports, 1.65 million barrels per day, mostly to China, depend on the Strait, making closure economically self-destructive. China, Iran’s largest oil customer, would exert significant pressure to keep the waterway open, as a spike in oil prices could disrupt its energy needs.

However, Iran’s capacity to disrupt traffic is a far more credible threat. U.S. intelligence estimates suggest Iran possesses 5,000 to 6,000 naval mines, which could be deployed rapidly to halt tanker traffic. During the Iran-Iraq War’s “Tanker War” in the 1980s, Iran used mines and missile attacks to target vessels, causing delays and spiking insurance premiums without fully closing the Strait. A report by bne IntelliNews notes that even a small number of mines could stop traffic immediately, as insurers would demand tankers anchor or reroute. Clearing mines could take weeks or months, especially if Iran reseeds them using its submarine fleet.

Iran’s Islamic Revolutionary Guard Corps (IRGC) has honed tactics like speedboat swarm attacks, limpet mine placements on ship hulls, and ship seizures, as seen in incidents like the 2019 detention of the Stena Impero. Its naval arsenal includes anti-ship cruise missiles, torpedoes, and drones, capable of harassing commercial and military vessels. The Houthi campaign in the Red Sea since October 2023, supported by Iran, demonstrates how limited attacks can collapse maritime traffic, offering a playbook for similar disruption in the Strait.

Potential Impact of Disruption

Even partial impedance of the Strait could have profound economic consequences. A 2012 Congressional Research Service report outlined how Iran could escalate from low-level harassment to violent attacks, causing immediate spikes in oil prices. Goldman Sachs and Rapidan Energy estimate that prolonged disruption could push oil prices above $100 to $150 per barrel, potentially doubling current levels. JPMorgan analysts warn that a “worst-case scenario” blockage could drive U.S. inflation to 5% and global oil prices to $120 per barrel.

Such a spike would hit consumers worldwide, with U.S. gas prices potentially rising to $5–$7 per gallon, according to X posts citing analyst Brian Krassenstein. Asian markets, particularly China, India, Japan, and South Korea, which rely heavily on Gulf oil, would face severe supply shortages. Saudi Arabia and the UAE have pipelines bypassing the Strait, but their capacity, 5.1 million and 1.5 million barrels per day, respectively, is insufficient to offset a major disruption. Countries like Iraq, Kuwait, and Qatar, with no alternative sea routes, would be particularly vulnerable.

Disruption would also invite international backlash. A closure attempt “would be an effective declaration of war against the Gulf states and the U.S.,” Eurasia analyst Gregory Brew told Axios. Iran risks alienating allies like China and regional neighbors improving ties with Tehran, such as Saudi Arabia. During the Iran-Iraq War, Iran refrained from closing the Strait to avoid provoking U.S. intervention, a precedent suggesting restraint despite rhetoric.

Current Context: Escalation and Restraint

Iran’s latest threats follow U.S. strikes on its nuclear facilities at Fordow, Natanz, and Isfahan on June 21, 2025, and Israel’s ongoing campaign against Iranian military and nuclear targets. On June 22, Iran’s parliament endorsed closing the Strait, though the final decision rests with the Supreme National Security Council and Ayatollah Ali Khamenei, per Press TV. Iranian lawmaker Esmail Kosari called closure “under serious consideration,” while Foreign Minister Abbas Araqchi said “all options are available.” Yet, Vice President JD Vance and U.S. Secretary of State Marco Rubio labeled such a move “suicidal,” citing Iran’s economic dependence on the Strait and the U.S. Navy’s presence.

The Risk of Miscalculation

While a full closure remains improbable, the risk of miscalculation looms large. Electronic interference with ship navigation systems near the Strait, reported by the Combined Maritime Forces’ JMIC on June 16, has already disrupted traffic. Iran’s history of seizing vessels, like the 2024 capture of a container ship, suggests it could escalate harassment if provoked further. The Houthi model, sustained, low-intensity attacks, shows how Iran could disrupt without closing the Strait, achieving economic impact while avoiding all-out war.

For now, the Strait remains open, with maritime trackers showing traffic continuing despite heightened tensions. But as Spencer Hakimian posted on X, “close to 50 large oil tankers” were scrambling to leave the Strait on June 21, signaling industry fears of imminent disruption. If Iran opts to impede traffic, the world could face a prolonged period of economic turbulence, even if the Strait never fully closes.

Sources: The Times of Israel, Axios, CNBC, Forbes, Newsweek, bne IntelliNews, U.S. Energy Information Administration, Reuters