President of Iran Hassan Rouhani threatened to close the Strait of Hormuz in response to potential sanctions that could be levied upon Iranian oil exports, threats which were echoed by the Islamic Revolutionary Guard Corps (IRGC). President Donald Trump has given countries until November 4, 2018, to stop importing petroleum from Iran. This wide-scale ban is part of a new campaign of confrontation and pressure against the Islamic Republic. This demand comes on the heels of the U.S. departure from the Joint Comprehensive Plan of Action (JCPOA), also known as the Iran nuclear deal, which was signed in 2015.
During negotiations, the JCPOA was marketed as the only option for curtailing Iran’s nuclear program short of war. Supporters of the deal routinely cited an increased risk of war in their arguments against exiting the deal and Rouhani’s statement, on the surface, appears to confirm such concerns. But how seriously should these threats be taken?
Closing the Strait of Hormuz has a regressive impact on Iran’s interests. As John Allen Gay and Geoffrey Kemp explain in War With Iran: Political, Military, and Economic Consequences:
Eighty-five percent of Iran’s imports come through the strait, and the oil exports so crucial to the Iranian government’s solvency mostly flow out of it. Iran would be cutting off its own lifeline if it closed the strait, and it would have to live on its already dwindling currency reserves. Iran would also be inviting attacks on its own oil facilities by vengeful neighbors, and it would isolate itself internationally.
So, in contemplating any Strait of Hormuz closure scenario, it should immediately be noted such a move by Iran amounts to one of desperation, employed only in a situation in which Tehran sees no other way out of its predicament. Therefore, a Strait closure is unlikely, the United States is well-aware of this, and the Iranian leadership probably realizes Washington can call its bluff any time. So why does Tehran continue to make such threats?
By threatening to close the vital waterway linking the oil-rich Persian Gulf with the world, through which approximately a third of the world’s petroleum is ferried, Iran stokes fears of war and economic crisis. This not only raises gas prices in anticipation of supply disruptions, but it also influences world opinion towards the direction of de-escalation, which would pressure the United States to back away from its own red lines. Given the number of countries that rely on Middle Eastern oil, including that of Iran, Tehran can craft a damning narrative that shows that the United States is generating a crisis to the world’s detriment.
Iran’s closure of the Strait would not involve employing its naval forces to physically occupy the waterways in a conventional sense. Rather, it would make the Strait impassable utilizing an Anti-Access/Area-Denial strategy (A2/AD) strategy. For Iran, mines would form the centerpiece of this strategy to turn the choke point into a no-go zone. Afterwards, it can use land-based anti-ship missiles (ASMs) to prevent clearance operations or to directly target enemy warships and civilian shipping. Should Iranian leadership deem it necessary to deploy naval forces, the IRGC possesses a large fleet of small fast-attack craft. Though lightly armed, the craft can prove a menace to conventional warships, via the use of “swarming” tactics to overwhelm adversaries and employ “hit-and-run” attacks that are notoriously difficult to counter. On a higher level, Iran could target United States and allied military facilities in the region or even civilian population centers with ballistic missiles as a means of deterrence.
The Israeli Wild-Card
Some observers are predicting a cataclysmic war between the Jewish state and Hezbollah in the near future. Given Hezbollah serves as Iran’s most prominent proxy, there are concerns such a conflict will draw Tehran in as well, risking a major regional conflagration. Israel has, in fact, already clashed numerous times with Iran-backed militias in Syria in recent weeks and months, raising the likelihood of direct warfare between Jerusalem and Tehran.
Although Washington does not possess a mutual-defense treaty with Jerusalem, the former would still support the latter’s war effort through the provision of armaments, logistics, intelligence support, among other products. Furthermore, the United States currently has troops deployed in Syria, Iraq, Jordan, and elsewhere throughout the region, along with the ongoing air war against the Islamic State of Iraq and the Levant (ISIL). In the event of a war between Israel and Hezbollah, potentially including Iran, it would take incredible diplomatic and military maneuvering to keep the United States directly out of the conflict.
The true course of any conflict is difficult to predict, but Washington should consider the possibility Iran may attempt to distract American support for Israel by threatening to close the Strait of Hormuz. By creating it crisis on the opposite end of the Middle East, Iran is not so much banking on forcing the United States to reduce support for Israel, but to overstretch its commitments, and create political and strategic costs the American people may not be willing to bear, given the generally controversial nature of the U.S.-Israeli relationship. Once more, the importance of narratives emerges—threatening Strait closure mounts pressure on the White House to find a diplomatic solution to the conflict, due to the dread and uncertainty portending a U.S.-Iran clash would conjure.
Once again, however, blockading Hormuz proves an ineffective move if the United States is willing to counter Iran’s provocations. This means Iran is more likely to respond with low-intensity, deniable warfare by utilizing cyberwarfare its deep roster of militias and terrorist groups.
Be it Lebanon’s Hezbollah, Gaza’s Hamas, or Iraq’s Popular Mobilization Forces, the Ayatollah is likely to call upon these players long before seriously considering closing the Strait of Hormuz. Hezbollah, in particular, is among the most well-connected of terrorist groups in the world, possessing links with Central and South American drug cartels. A worst-case scenario would involve Hezbollah exploiting these connections to carry out terrorism on American soil. At the very least, it can be expected that Iranian-backed militias like the PMU can be used to attack U.S. and coalition forces in Iraq and Syria as the anti-ISIL campaign continues. This would force the United States/coalition to contemplate escalating their involvement in the multiple civil wars in the region, or, to their obvious detriment, refrain from retaliation.
Barring further developments, this latest threat from Tehran to close the Strait of Hormuz will likely pass without incident. It will, however, create the potential for close encounters between U.S. and Iranian naval forces in the region, leaving open a window of heightened risk of miscalculation. Furthermore, the likelihood of a war between Hezbollah and possibly Iran continues to grow by the day. If or when that war happens, the United States and the coalition will find it difficult to stay out of the line of fire.