As communist forces of the Khmer Rouge closed in on Phnom Penh, Cambodia, U.S. forces executed Operation Eagle Pull April 12, 1975, successfully evacuating U.S. nationals and at-risk Cambodians.
It wouldn't be the last time U.S. forces would operate in Cambodia, which the victorious Khmer Rouge communists renamed Kampuchea.
In early May 1975, the Khmer navy seized seven Thai fishing boats, a South Korean freighter and a Panamanian vessel, and they fired on a Swedish ship, all of which entered inside the 12 nautical miles of territorial water Kampuchea claimed.
The United States recognized three nautical miles with ships outside that range as sailing in international waters.
The crisis began for the United States May 12, 1975, 50 years ago, when the U.S. container ship SS Mayaguez passed Poulo Wai, a group of islands in the Gulf of Thailand within 12 nautical miles of Kampuchea. At the time, the vessel was en route from Hong Kong to Sattahip, Thailand.
Khmer navy swift boats fired across the bow of Mayaguez, and seven Khmer Rouge soldiers boarded the vessel. The soldiers directed the ship's captain to sail to the Poulo Wai islands, where it anchored and where 20 additional Khmer Rouge soldiers boarded. Meanwhile, a crewman broadcasted a mayday call, which was received by the crew of an Australian vessel and relayed to the Americans.
President Gerald Ford was informed of the ship's seizure, and the White House issued a press release stating that the president considered the seizure an act of piracy.
Defense Secretary James R. Schlesinger ordered the military to locate Mayaguez. In the early morning hours of May 13, 1975, several P-3 Orion surveillance aircraft located the vessel at Poulo Wai. The planes drew enemy fire.
The captors then ordered the Mayaguez to sail to nearby Koh Tang Island, where it anchored. The Khmer Rouge then whisked away the crew to the mainland in fishing vessels.
The location of Mayaguez's captain and 39 crew was uncertain, which made rescue planning complicated.
About 230 Marines participated in the rescue attempt. The operation began a little before 7 a.m., May 15, 1975, when Air Force A-7D aircraft dropped tear gas on the Mayaguez. Three helicopters transported Marines to the frigate USS Harold E. Holt, which tied up beside the Mayaguez to facilitate boarding. At 7:25 a.m., Marines wearing gas masks boarded the ship but found no one aboard.
Helicopters transported Marines to two landing zones on Koh Tang. As it turned out, the crew was not on the island, and enemy forces were much stronger than expected. The Marines came under fire from rockets, mortars and small-arms fire from about 100 enemy forces.
Around 10 a.m., a fishing boat approached Koh Tang and was intercepted by the crew of the destroyer USS Henry B. Wilson. The Mayaguez captain and entire crew were aboard, and they were all safe.
The crew's captors hoped their release would encourage the U.S. to call off bombing runs on ports and naval bases on the mainland, which began earlier that morning.
With the Mayaguez recovered and the ship's crew safe, U.S. operations shifted toward the successful extraction of all military personnel on Koh Tang. The last 29 Marines were evacuated just after 8 p.m.
The final 41 names on the Vietnam Veterans Memorial Wall represent 25 Air Force pilots and crew, two Navy corpsmen and 14 Marines killed during the operation.
Of the 41, 23 Air Force personnel were lost in a helicopter crash in Thailand while preparing for the rescue, with the other 18 killed in and around Koh Tang.
The Khmer Rouge was ousted from power in 1979 when Vietnam invaded Kampuchea. In 1993, the monarchy was restored, and the nation once again became known as Cambodia. Also, in 1993, the U.S. established full diplomatic relations with Cambodia.
The Defense POW/MIA Accounting Agency conducted multiple missions to Koh Tang and the Cambodian mainland to search for the 18 killed. The trips resulted in the discovery of 13 sets of remains, all successfully identified and repatriated.
Marine Corps Lt. Gen. Richard E. Carey, who directed the Marines' participation in Operation Frequent Wind, the evacuation of Saigon, April 29 and 30, 1975, later said: "The Mayaguez rescue was the most classic example of assured failure with joint operations to that time. Unfortunately, the lesson was not learned, and the same mistakes were repeated in the Iranian hostage rescue operation in 1980."
In the final analysis, Carey said, the lack of accurate intelligence resulted in faulty decision-making driven by the desire to do something and to do it as quickly as possible.
Navy Cmdr. Richard B. Hughes, author of a July 1, 2016, article published in the National Defense University's Joint Force Quarterly, wrote: "The U.S. ground assault was ill-advised, a risky insertion of poorly prepared troops on an island where none of the crew was ever located. The crew's release was made in spite of, not because of, the island assault."
In 1996, the Mayaguez-Marine Corps Memorial was dedicated on the grounds of the U.S. Embassy in Phnom Penh. It lists the names of the 18 U.S. service members killed at Koh Tang, along with Marine Corps Sgt. Charles Wayne Turberville, an embassy security guard killed Sept. 26, 1971, in a Khmer Rouge grenade attack.