October 6, 2023 | Flash Brief

Strengthened U.S. Force Deters Iran’s Maritime Aggression

October 6, 2023 | Flash Brief

Strengthened U.S. Force Deters Iran’s Maritime Aggression

Latest Developments

A senior U.S. military official said on October 5 that American military units sent to the Middle East over the summer have proven effective in deterring Iranian maritime aggression. Lt. Gen. Alexus Grynkewich, commander of U.S. Air Forces Central, told reporters that the “increase in surface vessels, combined with our airpower, has deterred Iran from taking any actions against maritime shipping.”

According to a new FDD report, Iran harassed, attacked, or seized military and commercial vessels in at least 26 incidents from January 2021 to July 2023. This includes 12 seizures, seven attacks, and seven incidents of harassment. The regime in Tehran often threatens to cut off vital international shipping lanes, including the Strait of Hormuz, through which a fifth of the world’s oil transits.

Expert Analysis

“When it comes to threats to maritime freedom of navigation in the Middle East, Iran is the arsonist posing as the firefighter. When contemplating additional maritime aggression, Iran tends to think twice when the U.S. Navy and its partners show up.” — Bradley Bowman, Senior Director of FDD’s Center on Military and Political Power

“When confronted with U.S. Navy and partner vessels, Iranian forces almost always back down from their malign activities. Recent results show the wisdom of retaining sufficient forces in the Middle East to deter Iran and defend vital U.S. interests.” — Ryan Brobst, FDD Senior Research Analyst

Recent Iranian Malign Activity — and the Impact of U.S. Naval Power

In April and May, Iran unlawfully seized two tankers — the Marshall Islands-flagged oil tanker the Advantage Sweet and the Panamanian-flagged tanker Niovi — within a week of each other. The back-to-back seizures caused the U.S. Navy’s 5th Fleet — which is based in Bahrain — to increase its patrols.

In June, American and British ships thwarted an attempted hijacking of the Marshall Islands-flagged cargo ship Venture by Iran’s Islamic Revolutionary Guard Corps Navy fast-attack craft. In July, U.S. forces prevented the Iranian Navy from seizing two different commercial tankers. In one of those instances, the Iranian crew fired on the Bahamian-flagged Richmond Voyager oil tanker after attempting to stop the commercial vessel. The Iranian navy vessel departed when the guided-missile destroyer USS McFaul arrived.

U.S. Bolsters Forces to Deter Aggression

In May, White House spokesperson John Kirby announced, “The Department of Defense will be making a series of moves to bolster our defensive posture in the Arabian Gulf.” U.S. Central Command has used P-8 Poseidon maritime patrol aircraft, MQ-9 Reaper drones, unmanned surface vessels, A-10 aircraft, and guided-missile destroyers to deter Iran. In July, the Pentagon announced it was sending additional combat power to the region, including F-16 and F-35 fighter jets and the Navy destroyer USS Thomas Hudner. A week later, the Pentagon announced it would deploy the BATAAN Amphibious Readiness Group/Marine Expeditionary Unit (ARG/MEU).

Recent Analysis

Iran’s Maritime Aggression,” by Ryan Brobst and Bradley Bowman

U.S. Boosts Middle East Combat Power to Deter Iranian Aggression,” FDD Flash Brief

Securing Contested Waters: A Conversation with NAVCENT Commander Vice Adm. Cooper,” FDD Event


Iran Iran Global Threat Network Israel Military and Political Power U.S. Defense Policy and Strategy