Operations Prime Chance and Praying Mantis: USSOCOM’S First Test of Fire

Thirty-Eight Years Ago Our Military Fought Iran's in the Persian Gulf

A U.S. Navy Special Boat Unit Mark III pulls alongside a raft from the Iranian mine-laying ship Iran Ajar. US Department of Defense photo.

The controversial Operation Epic Fury is not the first time that our nation has actively deployed and utilized combat operations against Iran in the Persian Gulf. Twelve years ago I wrote an article for The Year in Special Operations 2013-2014 about the new Special Operations Command’s role in an authorized military operation against Iran’s military in 1987-1988. Though the focus of the article is the role of SOCOM and Special Operations units in action, it also touches on how the administration and military successfully navigated the complex and fraught political “minefield.” What follows is that article.

“In my view, to be successful in the northern Gulf we must establish intensive patrol operations to prevent the Iranians from laying mines.”—Rear Adm. Harold J. Bernsen, commander, Middle East Force, in an Aug. 6, 1987, memo to Gen. George B. Crist, USMC, commander, U.S. Central Command (CENTCOM)

By 1987, two of the most powerful nations in the Persian Gulf had been slugging it out for seven years in the costly stalemate known as the Iran-Iraq War. The escalation of attacks on neutral merchant shipping by both sides, referred to as the “Tanker War,” caused the United States to initiate Operation Earnest Will in July 1987. Initially designed to protect Kuwaiti tankers re-flagged as American ships, Earnest Will would also be the first combat test of the new U.S. Special Operations Command (USSOCOM) formed just three months earlier on April 16, 1987. Created in response to congressional action in the Goldwater-Nichols Department of Defense Reorganization Act of 1986 and the Nunn-Cohen Amendment to the National Defense Authorization Act of 1987, USSOCOM united all the services’ special operations components under a dedicated command equal to that of the other services. It was an independence long advocated by Special Operations Forces (SOF), and in Operations Prime Chance and Praying Mantis, part of Earnest Will, they would make an important first step in validating that decision.

To the uninitiated, the Persian Gulf appears to be an open, if somewhat narrow, body of water. The reality, so far as commercial oil tankers and blue-water navies are concerned, is that the Gulf more resembles a narrow valley in a long canyon dotted with numerous looming promontories. The combination of shallow depth with numerous islands, shoals, and oil platforms restricts deep-draft traffic to a few well-charted passages. With Iran bordering the entire eastern side of the Gulf from the Strait of Hormuz to Iraq, the result is a shooting gallery-style gauntlet more than 600 miles long from which Iran could stage attacks. As such, Rear Adm. Harold J. Bernsen, commander of Middle East Force at the time, quickly discovered that as a combat environment, the Persian Gulf gives the advantage to unconventional warfare tactics. So while Earnest Will, the escort of tankers by conventional warships, would be the high-profile—which is to say, highly publicized—side of the mission, the actual work interdicting Iranian attacks would be conducted covertly in Operation Prime Chance—making it, fittingly, the secret debut of USSOCOM.

Prime Chance’s primary adversary was Iran’s littoral fleet of small boats, mostly Swedish-built Boghammers and Boston whaler-type craft, used by the Pasdaran (Revolutionary Guards) to attack commercial shipping or lay mines, and Iranian oil platforms used as observation posts. The Pasdaran’s favored tactic for attacking ships was to swarm around a target and shoot at the vessel’s bridge and superstructure with 107 mm rockets, RPG-7 rocket-propelled grenade launchers, and machine guns. The intent was not so much to sink as to inflict as much damage as possible on the ship and crew.

Prime Chance was a joint special operations and conventional force operation utilizing personnel from the 160th Special Operations Aviation Regiment (Airborne)—the 160th SOAR, or “Night Stalkers”—SEALs, Special Boat Units, Marines, and the Navy. Prime Chance began with missions launched from Bernsen’s flagship, the command ship USS La Salle (AGF 3), and frigates USS Jarrett (FFG 33) and Klakring (FFG 42). Additional missions were planned to be staged from two large oil platform construction barges—the Hercules and the Wimbrown VII—located in Bahrain that were being converted into mobile sea bases (MSBs). Once operational, they would then be deployed in international waters near Iran’s Farsi Island in the northern Gulf. The conversion of the barges, and especially their deployed location, sparked a bureaucratic firestorm among traditionalists in the Pentagon opposed to the mobile sea base concept. Joint Chiefs of Staff critics of the plan claimed the MSBs would be irresistible targets dangerously vulnerable to air attack. With memories of the 1983 truck bomb attack on Marines in Beirut, Lebanon, still fresh, some went so far as to call the barges “Beirut Barracks.”

The crane aboard the barge Hercules prepares to life a Mark III patrol boat into the water for a patrol. the 65-foot aluminum patrol boats worked in pairs to monitor small boat activity in the Gulf. A specially equipped 160th SOAR UH-60 Black Hawk helicopter is parked on the helicopter pad. U.S. Department of Defense photo

Every operational aspect of the barges—from arms and ordnance storage and types, numbers, and placement of patrol craft and helicopters to pilot flight certifications, Navy health inspections of the barges’ food service areas, and more—was examined and argued by the Joint Chiefs.

Bernsen countered that Iranian air capability against the barges was a non-issue—Iran had only 20 operable F-4 Phantoms and few Harpoons. U.S. Central Command Commander Gen. George B. Crist, USMC, threw in an additional challenge: “Would you rather risk losing two oil barges or a billion-dollar ship?” This was a stinging reference to the Feb. 28, 1987, missile attack “by mistake” of Iraqi fighters on the frigate USS Stark (FFG 31) that killed 37 sailors, and a reminder that the northern Gulf was dangerous to high-value assets as well. On Sept. 17, Joint Chiefs Chairman Adm. William J. Crowe Jr., inspected the Hercules. While acknowledging the risk, Crowe decided using the barges as MSBs in the northern Gulf was the best way to go. With that, opposition ended. The Mk. III patrol boats conducted presence patrols, escorted convoys, and carried out intelligence missions beginning Sept. 9.

The 160th conducted nocturnal search-and-destroy missions using night-flight capable MH-6 (command and control) and AH-6 (attack) Little Bird helicopters equipped with forward-looking infrared (FLIR) and night vision goggles. Night Stalker pilots flew Little Birds an average of 30 feet above the sea.

Even though he advocated Prime Chance, Bernsen harbored some doubts about the Little Birds’ stealth capability, worried that Iranian ships would be able to identify and target them. The Night Stalker commander, Lt. Col. Bob Codney, set up an exercise to allay those concerns. On a moonless night, a pair of Little Birds was launched on a “patrol.” A half-hour later they reappeared—directly in front of the La Salle’s bridge. The first thing Bernsen or anyone else in the bridge knew of their presence was when they received the radio message: “Bang. You’re dead.” Bernsen was sold. From that point on, the call sign for the Night Stalkers in the Gulf was “Seabats.”

One of the 160th UH-60s on the flight deck of the barge Hercules as a Mark III patrol boat passes by during operations supporting Navy efforts to provide security for U.S.-flagged shipping in the Persian Gulf. The UH-60s were equipped with FLIR and a few other modifications, including a coat of gray paint that earned them the nickname “Grayhawks.” U.S. Department of Defense photo

The two most notable missions conducted in Prime Chance were the attack on the Iran Ajr, an amphibious landing craft converted into a minelayer, and the so-called “Battle of Farsi Island.”

On the night of Sept. 21-22, 1987, three Little Birds from the Jarrett flown by Bob “Flapper” Fladry and co-pilot Tom Leedom; Paul DeMilia and co-pilot Brian Collins; and Steve Chilton and co-pilot Terry Pena, all chief warrant officers, were flying patrol about 12 miles from the La Salle. It had been a boring patrol, with only marker buoys and dhows being spotted. With fuel starting to run low, the pilots were about to return to their ship when Fladry, in the command and control Little Bird, spotted the shape of a ship, the Iran Ajr. With DeMilia and Chilton breaking into a holding pattern a mile away, Fladry flew toward the ship. Fladry radioed in a contact report of a ship, work lights on and exhibiting no hostile action. Lt. Cmdr. Thomas Blankenship, captain of the Jarrett, had just ordered the flight to return to the ship when over the radio an alarmed Fladry stated, “They just turned all their lights off!”

This immediately raised everyone’s suspicions. Flying in a holding pattern 200 meters astern of the ship, Fladry went on to report deck activity in which crew members appeared to be “pushing shopping carts on deck” and into the water. Bernsen immediately identified the shopping carts as mines and ordered the helicopters to ready their guns while he got on the Satcom to Washington, D.C., to request permission to attack. After a third mine had been pushed overboard, Bernsen gave permission to “use whatever force is necessary” to stop the mine-laying.

Chilton flew into attack position perpendicular to the Iran Ajr’s hull, with DeMilia right behind. For 10 minutes, Chilton and DeMilia raked the minelayer with rocket and minigun fire. With the Iran Ajr dead in the water and burning from several small fires, the surviving members of the Iranian crew abandoned ship.

A SEAL team boarded the Iran Ajr at dawn. A search of the vessel discovered nine mines still on its deck, as well as a logbook detailing the number and location of the mines that had been laid and other intelligence. Five Iranians had been killed and 26 captured, later to be repatriated. After they had gathered all the intelligence they could, the SEALs scuttled the Iran Ajr.

In September, the Hercules was operational and towed into position in international waters a few miles away from Farsi Island. Navy SEAL Lt. Cmdr. Paul Evancoe was the officer in charge of the mixed contingent, which, in addition to the SEALs, Night Stalkers, and U.S. Marines, included about 30 foreign nationals, part of the lease contract terms specified by the barge’s owner. The Night Stalker pilots stationed on theHercules included Fladry, Leedom, DeMilia, Collins, Pena, and Chief Warrant Officer Bob Witter.

Two members of a Navy special warfare unit practice firing rifles from the deck of the barge Hercules during Operation Prime Chance. One sailor (foreground) is firing a .50-caliber sniping rifle, the other an M600 7.62 mm sniping rifle. U.S. Department of Defense photo

On the night of Oct. 8, they were escorting a reconnaissance mission along a section of the island’s coast by Special Boat Unit craft. At a specified time, they were to rendezvous at the Middle Shoals Buoy with a surface group from the Hercules containing a Seafox and two patrol boats. But when they arrived at the waypoint, they were surprised by three Iranian patrol ships that took the Little Birds under fire. The helicopters returned fire, sinking the vessels. American SOF craft arrived and rescued six Iranian survivors, two who later died of wounds. A short time later, radar screens detected what appeared to be as many as 40 small Iranian vessels heading toward the Hercules. The Americans prepared their defenses, but as the USS Thach (FFG 43) sped toward the Iranian vessels on an intercept course and six armed Little Birds orbited overhead, the contacts reversed course. The Hercules did not come under attack. Some later speculation suggested that the attack was possibly a false radar read, though other sources claim the vessels had been visually identified.

The next major action involving American and Iranian forces occurred on Oct. 19, 1987, in Operation Nimble Archer. During the spring and summer, Iran, which had seized Iraq’s strategic Al Faw Peninsula, had been deploying Silkworm anti-ship missiles there, posing a serious threat to the ships harbored in and around the port of Kuwait City, approximately 60 miles southwest. In early September, Iran had fired two Silkworms, the first of which harmlessly landed in Gulf waters and the second hitting an uninhabited beach about two miles south of an oil loading terminal. On Oct. 15, however, the tanker Sungari was heavily damaged by a Silkworm attack, and on Oct. 16, another tanker, the Sea Isle City, was also hit. In response, the American military command decided that instead of hitting the Silkworm sites on the peninsula, its forces would attack farther south in Iran’s Rashadat oil field located across the Gulf from Bahrain and Qatar. Two inactive oil platforms were being used there to stage attacks by Pasdaran forces and as ship traffic observation posts.

On Oct. 17, six U.S. Navy warships approached the platforms. Cmdr. G.J. O’Donnell, captain of the frigate USS Thach, which had assisted in the Oct. 8 action, radioed the two platforms, warning them of the warships’ intentions and advising personnel aboard to leave, which the Iranians did. Once the Iranians were clear, four destroyers—USS Hoel (DDG 13), Leftwich (DD 984), John Young (DD 973), and Kidd (DDG 993)—commenced firing. One platform caught fire, but the other platform, even though it was hit by almost 1,000 rounds, remained standing. A SEAL team boarded the platform and, after gathering a variety of intelligence, destroyed it with explosives.

But the Iranian government refused to back down. On Oct. 22, it launched a Silkworm attack on Kuwait’s Sea Island oil terminal, which handled a third of the country’s oil exports. It also ramped up its anti-shipping campaign, staging 27 attacks in November and December that sank one merchant ship and rendered two others CTL (constructive total loss). The increased attacks continued into 1988.

When the Wimbrown VII became operational in December, original plans called for it to be stationed at the opposite end of a 100-mile area of operations off Farsi Island. That was changed, and the smaller barge was deployed 10 miles north of the Hercules in order to provide mutual support and help relieve the barge’s overstretched pilots and crews.

The captured Iranian minelayer Iran Air with a U.S. Navy landing craft alongside. U.S. Navy SEALs boarded and captured the ship during Operation Prime Chance after it had been attacked by 160th helicopters. The SEALs found mines and vital intelligence aboard the minelayer. DoD photo

In February 1988, Rear Adm. Anthony Less relieved Bernsen as Middle East Force commander. The following month, Less assumed a more aggressive role regarding Iranian shipping attacks.

Navy captains operating in the Gulf were frustrated that their rules of engagement prevented them from protecting neutral non-American-flagged vessels, forcing them to remain spectators when those ships came under attack. Though he upheld U.S. policy, Less instructed his captains to “explore the gray area” between shooting and remaining spectators. His instructions, which specifically targeted Iranian actions, ran the risk of escalating the conflict by causing Iran to no longer regard the United States as a neutral party.

On April 14, 1988, the U.S. frigate Samuel B. Roberts (FFG 58) was severely damaged by a mine that almost tore the ship in half. Heroic action by her damage control crew saved the ship. Upon receiving the news, the American high command began discussing retaliation. The State Department, wishing to avoid escalation, stated that any response needed to be “proportionate.”

Crowe proposed that retaliation be the destruction of an Iranian warship. And in an unusual move, he went so far as to identify the ship, the frigate Sabalan, as its captain had ordered the cold-blooded machine-gunning of survivors of sunken tankers.

Crist recommended the destruction of oil platforms that were also used as Pasdaran observation posts.

Less recommended a combined air and Tomahawk missile attack on Iran’s Bandar Abbas naval base on the Strait of Hormuz.

President Ronald Reagan sided with Crist, and two Iranian platforms in the Sirri and Sassan oil fields located in the lower half of the Gulf off the coasts of Qatar and the United Arab Emirates were identified as the targets. The stage was now set for Operation Praying Mantis, the largest major surface action conducted by the U.S. Navy since World War II.

Less organized the attacking force into three surface action groups (SAGs). SAG Bravo, commanded by Capt. James B. Perkins and containing the USS Merrill (DD 976), Lynde McCormick (DDG 8), and Trenton (LPD 14) with its Marine Air-Ground Task Force, was assigned the Sassan platform. SAG Charlie, commanded by Capt. James F. Chandler and containing the Wainwright (CG 28), Simpson (FFG 56), and Bagley (FF 1069), which carried a SEAL team, was assigned the Siri platform. SAG Delta, commanded by Capt. Donald A. Dryer and containing Jack Williams (FFG 24), O’Brien (DD 975), and Joseph Strauss (DDG 16), was assigned security patrol duties near the Strait of Hormuz. Additional support in the form of air cover was provided by the Enterprise (CVN 65) on station in the Gulf of Oman, and Saudi-based airborne warning and control system AWACS and tanker aircraft.

Marines inspect a ZU-23 23 mm automatic anti-aircraft gun on the Iranian Sassan oil platform. Marines attacked, occupied, then destroyed the platform as part of Operation Praying Mantis, which was launched after the guided-missile frigate USS Samuel B. Roberts (FFG 58) struck a mine on April 14, 1988. US DoD photo

Operation Praying Mantis commenced on April 18, 1988. At 6 a.m., Perkins broadcast warnings in English, Arabic, and Farsi to the Iranians on the Sassan platform, telling them to abandon it. About 30 Iranians complied, but some remained and fired upon the SAG with a 23 mm cannon. The Merrill returned fire, destroying the cannon and causing the remaining Iranians to evacuate in a rubber raft. At the same time, Iranian F-4 Phantoms approached, but turned away without engaging SAG Bravo. A contingent of Marines was then air lifted to the platform. After a gathering of intelligence material, explosive charges were set, and the platform was so severely damaged it was rendered useless.

At about the same time, SAG Charlie was conducting similar action on the Siri platform once all the Iranians had abandoned it. At 10:48, an approaching Iranian frigate, Joshan, was identified. The Joshan ignored three warnings issued from the Wainwright, and launched a Harpoon missile that narrowly missed the cruiser. SAG Charlie returned fire with SM-1 and Harpoon missiles, heavily damaging the Joshan. The burning frigate was then sunk with gunfire. As this was going on, the Wainwright engaged an Iranian F-4, damaging it and forcing the fighter to retire.

This was followed by a chain of events throughout the Persian Gulf. A force of Pasdaran small craft attacked a number of targets in the Mubarek oil fields in the southern Gulf, hitting several ships. These small craft came under fire from A-6 Intruders from the Enterprise that sank one of the Iranian vessels. The Iranian frigate Sahand, sister ship to the Sabalan, attempted to engage Enterprise aircraft, but found itself on the receiving end of bomb and Harpoon missile strikes that quickly sank it. The Sabalan almost followed her. That afternoon it attempted to shoot down an A-6, and the Intruder dropped a bomb down the frigate’s smoke stack. Dead in the water with its engines destroyed, it was saved from being sunk when a follow-up air strike was called back. All told, Iranian losses were three oil platforms heavily damaged, six surface vessels sunk, one heavily damaged, and an unknown number of casualties. American losses were one AH-1T attack helicopter and its two-man crew.

Iranian attacks on merchant shipping dramatically fell after that. Operation Earnest Will would continue until Sept. 26, 1988. When it concluded, it was judged a success. The only major negative was the shoot-down of Iran Air Flight 655 by the USS Vincennes (CG 49) in which all passengers and crew perished. In the political and diplomatic arena, America’s strategic goals of protecting Kuwaiti – and later other, neutral – shipping, standing up to Iran without escalating the conflict, keeping the Soviet Union out of the Gulf, and proving its worth as a friend of the Arab world had been largely achieved. For special operations forces, USSOCOM had proved its worth with its successful completion of a variety of missions. Much work remained ahead, but an important first step had been taken.