Do US and Iranian navies need a hotline in the Gulf?

The US-Iran conflict reached another escalation point April 15 when 11 Islamic Revolutionary Guard Corps (IRGC) navy speedboats harassed US warships in the Gulf, coming as close as 10 yards, despite multiple warnings. In response, President Donald Trump, in an oddly phrased tweet April 22, said he had directed the US Navy to "shoot down and destroy" any Iranian boats that again harassed US ships. The escalation this time was almost entirely on Iran’s shoulders. Trump’s threat has an ominous side, yet it could help contain the situation if it acts as a deterrent.

The harassing behavior by IRGC boats, crossing the bows and sterns of the US ships, is nothing new. In 2015, the US Navy reported 25 such incidents, which it politely terms "unsafe and unprofessional conduct." In 2016, there were three dozen more. These provocative actions took place while the United States and Iran were negotiating, and then implementing, the Joint Comprehensive Plan of Action. While Iran denies any malfeasance, US Navy officers are trained to capture all such incidents on video. In the latest case, the camera clearly shows which side was at fault. Iranian Foreign Minister Mohammad Javad Zarif retorted that US forces have no business in the Gulf to begin with, over 7,000 miles away from the US homeland.

Naval harassment by the IRGC largely stopped in autumn 2017, although electronic interference did not stop. The former US 5th Fleet commander, Vice Adm. John Miller, attributes this change in IRGC speedboat behavior to Iranian concern that the new American president would respond forcefully, although this does not explain why Iran continued the activity for over half a year after his inauguration. “Maybe it just took a while for them to realize it was not a good idea to push [Trump],” Miller said.

It is too soon to judge whether the April 15 activity was a return to the old pattern or a one-off move, designed to test US responses. It is ominous, however, that it came the day after the IRGC navy boarded and detained a Hong Kong-flagged Taiwan oil tanker. If there was one area of Iranian behavior that the US administration could unequivocally point to as having changed for the better as a result of Trump’s hard-line posture, it was the let-up in naval harassment. If Iran returns to the old harassment playbook, it will underscore the futility of the maximum pressure campaign.

In defiance of the 12 demands made by US Secretary of State Mike Pompeo in a May 2018 speech, Iran has done the opposite on nearly every point. It expanded its nuclear program, obfuscated the prior military dimensions of that program, denied international inspector access requests, furthered its ballistic missile development, maintained its forces in Syria, continued military support for the Houthi rebels, aided attacks by its proxies in Iraq, kept dual Iran-US citizens in detention and threatened international shipping. Stopping harassment of US naval forces now has to be added as an additional demand. Iran’s behavior has become more troublesome in almost every respect, much of it in response to US “maximum pressure.”

Trump’s tweet was intended as a warning to Iran, to deter further harassment. Although Trump characterized his response as a “direction” to US forces, no such directive has come to light. There is no need for it, because the US Navy already has clear rules of engagement when dealing with the IRGC. Navy officials know how to respond to harassment without escalating and when lethal force is warranted, Miller said.

Some experts, however, believe that the US Navy may need to reinforce Trump’s words with action. Michael Eisenstadt, director of the Washington Institute's Military and Security Studies Program, finds it “disconcerting how brazenly dangerous” the IRGC was in coming so close to US ships. He suggests the Navy ramp up its response to any IRGC gunboats approaching too closely by use of nonlethal means such as “entanglement systems” — what he described as glorified fishing nets — to foul up the approaching boats’ propellers. He cautioned, however, that there is a downside, because the IRGC could do the same in response, disabling the more expensive US ships.

The downside risk in Trump’s threatening language is that he may now feel compelled, for credibility reasons, to order a kinetic attack if Iran, out of inertia, crosses his red line by continuing the harassment. The IRGC, having issued its own threat to “destroy any American terrorist force in the Persian Gulf that threatens security of Iran's … ships," may then itself feel bound to protect its credibility by taking forceful action.

Already, the IRGC is likely to feel duty-bound to exact revenge over the January 2020 assassination of its Quds Force commander Qasem Soleimani — not just to restore honor, but because Iran has its own need to reestablish deterrence. This perceived need to strike back at the United States may have contributed to the April 15 harassment. But the latter action was both too small-scale and too overt for this purpose. Iran is surely planning something lethal and not immediately attributable, so as to allow for an escalation plateau.

As a means of de-escalating, the International Crisis Group has recommended that the United States and Iran open a military communication channel facilitated by a third party such as Oman, going beyond the current system of routine messages between ships in proximity. Arranging a deconfliction hotline makes eminent sense.

Over the years, Iran has resisted suggestions from US government and nongovernmental players to establish a mechanism similar to the “incidents at sea” agreements that Washington has had with Moscow and Beijing. During the latter years of the Obama administration, this may not have been needed, because there was a better channel in the direct telephone line between Zarif and US Secretary of State John Kerry and their respective staffs. With Iran-US diplomacy dead in the water, the respective navies need a hotline of their own. Twitter was never cut out to be a de-escalation tool.