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Policy Analysis

PolicyWatch 3122

Rumors of War: Responding to Iranian Pushback in the Gulf

Michael Eisenstadt and Farzin Nadimi

Also available in العربية فارسی

May 17, 2019

Washington should reduce tensions, open lines of communication, and restore deterrence, though managing the contradictions between these objectives will be challenging.

On May 12, four ships—two large Saudi crude oil tankers and smaller Emirati and Norwegian tankers—were damaged in what various international authorities described as acts of sabotage, with U.S. officials attributing them to Iran or its proxies. Although explosive devices may have been used, no casualties or oil leaks were reported.

The attacks appeared to be well planned and executed, as the vessels were five to twelve kilometers from each other off the coast of Fujairah, UAE. If Iran was indeed involved, the operation could have been the work of either the regular navy or the Islamic Revolutionary Guard Corps Navy (IRGCN). Both are capable of such attacks, though Fujairah is outside the Persian Gulf and therefore in the regular navy’s area of responsibility.

Two days after the ship attacks, drones struck Saudi Aramco oil pumping stations at Afif and al-Duwadimi along the East-West Pipeline that traverses the center of the kingdom, causing a fire at one of them. Yemen’s Iranian-backed Houthi rebels took credit for the attack, reportedly their first operation against that pipeline.

All of these incidents occurred just days after the U.S. government issued warnings about possible Iranian or proxy attacks, with potential targets including U.S. military personnel in Iraq and Syria and military/commercial shipping in the region. The strategic logic of the attacks (see below) is one of several reasons to believe Iran was behind them, as is the fact that the pro-Hezbollah al-Mayadeen television network in Lebanon was the first to report the events off of Fujairah.

On May 15, the State Department ordered the departure of non-emergency personnel from the U.S. embassy in Baghdad and consulate in Irbil, apparently in response to threats against U.S. personnel from Iran’s local proxies. Soon thereafter, Germany and the Netherlands temporarily suspended their military training programs in Iraq. These developments may indicate that Iran is planning follow-on attacks, whether to deter Washington from responding to the initial attacks or to counter perceived U.S. escalatory moves (e.g., the recent deployment of a carrier strike group to the Gulf of Oman). Although President Trump and Supreme Leader Ali Khamenei have stated that war is not in the cards, the actions of forces on the ground could produce just such an outcome if not managed carefully.


One indicator of possible Iranian sponsorship is that the attacks seem to share a common strategic logic centered on the Strait of Hormuz. Fujairah is the site of an oil pipeline originating in Abu Dhabi that allows the UAE and partner countries to export 1.5 million barrels per day of crude while bypassing that narrow, vulnerable strait. Iran has repeatedly disparaged the project, describing it as a futile effort to make the strait redundant. In Saudi Arabia, the East-West Pipeline has the capacity to transport five million barrels per day from eastern oil fields to Red Sea export terminals, likewise bypassing the strait (though in practice it runs at less than half that daily capacity). Iranian leaders may have hoped to send a message that in a crisis or war, they can disrupt oil exports not only through the strait (something they have long claimed), but also through alternate routes.

In doing so, they were likely responding to the Trump administration’s April 22 announcement that it would cease granting waivers for sanctions on the purchase of Iranian oil—a decision aimed at driving the regime’s oil exports to zero as part of the president’s “maximum pressure” campaign. Since the Iran-Iraq War, Tehran has warned that if it cannot export oil through Gulf waters, then no one will. IRGCN commander Alireza Tangsiri repeated this threat on April 22: “If we are prevented from using [the Strait of Hormuz], we will close it.” The attacks reinforced this point.

In response, Washington accused Iran of moves that suggested attacks of some kind were imminent, then announced on May 6 that the USS Abraham Lincoln strike group and four B-52H bombers were deploying to the region. Meanwhile, National Security Advisor John Bolton warned that “any attack on United States interests or on those of our allies will be met with unrelenting force.”

The main question, however, is not U.S. military capabilities in the region, but U.S. credibility. If Iran is behind the shipping and pipeline attacks, then it has clearly demonstrated both its willingness to defy Bolton’s warning and its ability to disrupt the region’s oil trade. Although oil shipments have continued unhindered, prices and insurance premiums quickly spiked, and further attacks could cause larger ripples. Moreover, by avoiding casualties and hitting merchant vessels owned by U.S. regional allies and a smaller EU state, the attacks limited the potential for escalation with the United States. In short, Iran apparently hoped to undermine Washington’s credibility, constrain its freedom of action, and yet avoid a fight—at least for now.


Assuming that the Trump administration’s claims about Iranian threats are supported by credible intelligence and forensic evidence, the events of the past week have highlighted several potential problems with the current U.S. approach:

Deterrence failures. The attacks seemed to show that warnings and force deployments are not always sufficient to deter Tehran or its partners from crossing Washington’s stated or implicit redlines. Part of the reason for this gap is that the administration crossed Iran’s own redlines—namely, the stated U.S. goal of reducing oil exports to zero threatened to further undermine the Iranian economy and exacerbate domestic unrest. Tehran now seems prepared to escalate further if the United States responds militarily or tries to preempt future operations.

Miscalculation of risk vs. gain. Prudence dictates that Washington avoid crossing an adversary’s redlines unless vital U.S. interests require otherwise. In the latter case, it should be prepared for a forceful response. By trying to cut off all Iranian oil exports, the administration assumed greatly increased risk in pursuit of uncertain gains.

Loss of credibility. The administration has a double credibility problem. First, the president’s oft-stated desire to avoid further Middle Eastern wars and pull U.S. troops out of the region may have tempted Iran to test him. Second, many Americans and U.S. allies blame the administration for the current crisis due to its withdrawal from the nuclear deal last year. They are now skeptical of any administration claims about Iran and believe officials want to provoke a war. These perceptions will hinder an effective U.S. response to the crisis.

Iran’s willingness to gamble. Tehran and its partners seem willing to risk crossing American redlines, but in a cautious manner that avoids the type of wide-scale armed conflict they could not hope to win militarily. As noted previously, they avoided hitting U.S. targets and apparently tailored the attacks to limit the potential for harm and escalation. This careful approach may have been intended to pressure the United States to step back from its efforts to cut Iran’s oil exports to zero.


In light of these problems, the administration should take steps to reduce the chances of escalation while still advancing vital U.S. interests:

Allay critics. To help assuage domestic and foreign critics who are skeptical about its claims and intentions regarding Iran, Washington should reveal as much intelligence as possible about threats to U.S. personnel, Gulf oil, and maritime freedom of navigation. This includes publishing the forensic evidence pertaining to the Fujairah tanker attacks, which credible NGOs can then independently assess. Although greater transparency is unlikely to sway those who fundamentally distrust the administration, it might help garner support for efforts to formally condemn Iran’s threats to freedom of navigation in the Persian Gulf.

Open communications, reduce tensions. Washington should try to open lines of communication with Tehran to reduce the possibility of miscalculation, and perhaps jumpstart negotiations. Meanwhile, the administration should quietly slow the phase-in of its latest energy sanctions—for instance by permitting continued Iraqi imports of Iranian electricity and gas to generate power throughout the hot summer, and by allowing foreign companies to receive shipments of Iranian oil to repay debts.

Harden and protect. Although the attacks did little real harm to Gulf energy exports, the vulnerability of the region’s critical oil infrastructure and sea lines of communication has been exposed. Many steps can be taken to further harden this infrastructure and protect sea lanes, but there is no way to safeguard every vulnerable facility and vessel. In the end, restoring deterrence is the single most important thing the United States can do to bolster such protections.

Restore deterrence through message discipline. Washington should avoid the kind of actions that have repeatedly undermined its deterrence posture toward Iran. For one, U.S. officials should stop sending mixed messages about America’s intentions in the region. They should also eschew imprecise language (e.g., the oft-repeated “Iran has been put on notice”) and bombastic rhetoric (“unrelenting force”) when conveying deterrence threats, especially if such words are not backed up by a commitment to act. Moreover, as previous administrations learned the hard way, Washington should not define explicit redlines unless it is willing to enforce them. Nor should it cross Iran’s redlines unless vital interests are at stake, or unless it is prepared to deal with a forceful Iranian response.

America’s deterrence posture is already diminished, however, so the administration needs to undertake some sort of concrete response to the Gulf attacks in order to restore its credibility. Yet it should avoid actions that could draw it into a deeper conflict with Iran, inflame members of Congress, and further alienate allies.

Consider covert action. One way to square the “deter but don’t overreact” circle is to consider low-profile, deniable actions that impose significant material costs on Iran, thereby complicating the regime’s efforts to calibrate risks and costs in the future. Tehran should understand that two can play the game of plausible deniability. As with overt deterrence, however, covert action could come into friction with parallel U.S. efforts to reduce tensions and open lines of communication. Managing these contradictions will likely be the administration’s biggest policy challenge going forward.

Expand U.S. shows of force. The administration has made a number of notable military moves already: in addition to deploying a carrier strike group to the region and sending four B-52s to al-Udeid Air Base in Qatar, it transferred more F-15C fighters to al-Dhafra Air Base in the UAE (augmenting the F-15Cs and F-35s already there), announced the deployment of a Patriot antimissile battery, and made plans for the USS Arlington amphibious transport ship to replace part of the USS Kearsarge amphibious readiness group currently in the area. Yet more deployments may be needed if Washington hopes to signal that it has viable options at hand in the event of further Iranian escalation—for example, a second carrier strike group and/or additional bombers. As emphasized above, however, such deployments will not yield the desired deterrent effect unless the United States also repairs its damaged credibility.

Prioritize crises. Foreign crises are challenging for even the most seasoned administrations, and President Trump’s team is concurrently caught up in tensions with Iran, China, North Korea, and Venezuela. The mental bandwidth and physical capacity available to deal with such situations are finite, and spreading America’s military resources and the attention of its senior decisionmakers too thinly around the globe risks courting disaster in one or more places. As the United States works through the current crisis with Iran, it should deescalate in these other arenas.

Michael Eisenstadt is the Kahn Fellow and director of the Military and Security Studies Program at The Washington Institute. Farzin Nadimi is an associate fellow with the Institute, specializing in the security and defense affairs of Iran and the Gulf region.