Cambodian Campaign.Operation Binh Tay

DATE: 29/05/2025

TIME (GMT): 18:00

ERA: Vietnam

MAP(S): Prei Khmaoch Luong

TYPE: COOP

TEAMSPEAK: ts1.biaarma.com

GAME: Arma 3

EVENT: Official

AUTHOR(S): Aris and Lord for Brothers in Arms

SLOTS: 61 / 70

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RATING: (6)

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The Cambodian campaign was a series of military operations conducted in eastern Cambodia in mid-1970 by South Vietnam and the United States as an expansion of the Vietnam War and the Cambodian Civil War. Thirteen operations were conducted by the Army of the Republic of Vietnam (ARVN) between April 29 and July 22 and by U.S. forces between May 1 and June 30, 1970.

The objective of the campaign was the defeat of the approximately 40,000 troops of the People s Army of Vietnam (PAVN) and the Viet Cong (VC) in the eastern border regions of Cambodia. Cambodian neutrality and military weakness made its territory a safe zone where PAVN/VC forces could establish bases for operations over the border. With the US shifting toward a policy of Vietnamization and withdrawal, it sought to shore up the South Vietnamese government by eliminating the cross-border threat.

A change in the Cambodian government allowed an opportunity to destroy the bases in 1970, when Prince Norodom Sihanouk was deposed and replaced by pro-U.S. General Lon Nol. A series of South Vietnamese–Khmer Republic operations captured several towns, but the PAVN/VC military and political leadership narrowly escaped the cordon. The operation was partly a response to a PAVN offensive on March 29 against the Cambodian Army that captured large parts of eastern Cambodia in the wake of these operations. Allied military operations failed to eliminate many PAVN/VC troops or to capture their elusive headquarters, known as the Central Office for South Vietnam (COSVN) as they had left a month earlier, but the haul of captured materiel in Cambodia prompted claims of success.

The PAVN had been utilizing large sections of relatively unpopulated eastern Cambodia as sanctuaries into which they could withdraw from the struggle in South Vietnam to rest and reorganize without being attacked. These base areas were also utilized by the PAVN and VC to store weapons and other material that had been transported on a large scale into the region on the Sihanouk Trail. PAVN forces had begun moving through Cambodian territory as early as 1963.Cambodian neutrality had already been violated by South Vietnamese forces in pursuit of political-military factions opposed to the regime of Ngo Đinh in the late 1950s and early 1960s.In 1966, Prince Norodom Sihanouk, ruler of Cambodia, convinced of eventual communist victory in Southeast Asia and fearful for the future of his rule, had concluded an agreement with the People s Republic of China which allowed the establishment of permanent communist bases on Cambodian soil and the use of the Cambodian port of Sihanoukville for resupply.

During 1968, Cambodia s indigenous communist movement, labeled Khmer Rouge (Red Khmers) by Sihanouk, began an insurgency to overthrow the government.While they received very limited material help from the North Vietnamese at the time they were able to shelter their forces in areas controlled by PAVN/VC troops.

In mid-April 1970 Abrams and Chief of the South Vietnamese Joint General Staff (JGS) General Cao Van Vien discussed the possibility of attacking the Cambodian base areas. Cao passed on these discussions to South Vietnamese President Nguyen Van Thieu who verbally ordered the JGS to instruct ARVN III Corps to liaise with MACV for operations in Cambodia. In late April Thieu sent a secret directive instructing the JGS to conduct operations in Cambodia to a depth of 40–60 km from the border.By April 1970, the PAVN-Khmer Rouge offensive in Cambodia was going well and they had taken all five of Cambodia's northeastern provinces and Kissinger predicated to Nixon that the Lon Nol regime would not survive 1970 on its own.

In response to events in Cambodia, Nixon believed that there were distinct possibilities for a U.S. response. With Sihanouk gone, conditions were ripe for strong measures against the base areas. He was also adamant that some action be taken to support The only government in Cambodia in the last twenty-five years that had the guts to take a pro-Western stand.As the poorly-trained FANK went from defeat after defeat, Nixon was afraid that Cambodia would go down the drain if he did not take action.

Nixon then solicited proposals for actions from the Joint Chiefs of Staff and MACV, who presented him with a series of options, a naval quarantine of the Cambodian coast or the launching of South Vietnamese and American airstrikes, the expansion of hot pursuit across the border by ARVN forces, or a ground invasion by ARVN, U.S. forces, or both.

Nixon went to Honolulu to offer his congratulations to the Apollo 13 astronauts who had survived a malfunction on their spacecraft and while there, met the Commander in Chief, Pacific Command, Admiral John S. McCain Jr., who was the sort of aggressive, pugnacious military man he admired the most.McCain drew for Nixon a map of Cambodia that depicted the bloody claws of a red Chinese dragon clutching half of the country and advised Nixon that action was needed now.Impressed by Admiral McCain s performance, Nixon brought him back to his house in San Clemente, California, to repeat it for Kissinger who was unimpressed.Kissinger was upset that Thọ had temporarily ended their secret meetings in Paris and shared Nixon s inclinations to lash out against an enemy. Kissinger regarded Thọ like all Vietnamese as insolent.

During a televised address on April 20, Nixon announced the withdrawal of 150,200 U.S. troops from South Vietnam during the year as part of the Vietnamization program.This planned withdrawal implied restrictions on any offensive U.S. action in Cambodia. By early 1970, MACV still maintained 330,648 U.S. Army and 55,039 Marine Corps troops in South Vietnam, most of whom were concentrated in 81 infantry and tank battalions.

On April 22 Nixon authorized the planning of a South Vietnamese incursion into the Parrot s Beak (named for its perceived shape on a map), believing that Giving the South Vietnamese an operation of their own would be a major boost to their morale as well as provide a practical demonstration of the success of Vietnamization.At the meeting of April 22, both Rogers and the Secretary of Defense Melvin Laird proposed waiting to see if the Lon Nol regime could manage to survive on its own.Kissinger took an aggressive line, favoring having the ARVN invade Cambodia with American air support.

The Vice President, Spiro Agnew, the most hawkish member of Nixon s cabinet, forcefully told Nixon to avoid pussyfooting around and invade Cambodia with American troops.On April 23, Rogers testified before the House Appropriations Subcommittee that the administration had no intentions...to escalate the war. We recognize that if we escalate and get involved in Cambodia with our ground troops that our whole program [Vietnamization] is defeated.

Nixon then authorized Abrams to begin planning for a U.S. operation in the Fishhook region. A preliminary operational plan had actually been completed in March, but was kept so tightly under wraps that when Abrams handed over the task to Lieutenant general Michael S. Davison, commander of II Field Force, Vietnam, he was not informed about the previous planning and started a new one from scratch.Seventy-two hours later, Davison s plan was submitted to the White House. Kissinger asked one of his aides to review it on April 26, and the National Security Council staffer was appalled by its sloppiness.

The main problems were the pressure of time and Nixon s desire for secrecy. The Southeast Asia monsoon, whose heavy rains would hamper operations, was only two months away. By the order of Nixon, the State Department did not notify the Cambodian desk at the US Embassy, Saigon, the Phnom Penh embassy, or Lon Nol of the planning. Operational security was as tight as General Abrams could make it. There was to be no prior U.S. logistical build-up in the border regions which might serve as a signal to the communists. U.S. brigade commanders were informed only a week in advance of the offensive, while battalion commanders got only two or three days notice.

Planning for any eventuality the North Vietnamese started planning emergency evacuation routes in the event of a coordinated assault by Cambodians from the west and South Vietnamese from the east. After the Cambodian coup, COSVN was evacuated on 19 March 1970.While the Provisional Revolutionary Government of the Republic of South Vietnam (PRG) and PAVN-VC bases were preparing to also move to the north and safety they came under aerial bombardment from B-52 bombers on 27 March.As laid out by the evacuation plans General Hoang Van Thai planned to have three divisions to cover the escape.The 9th Division would block any movement from the ARVN, the VC 5th Division would screen any FANK forces and the 7th Division would provide security to the civilian and military members of the PAVN/VC bases.

Operation Binh Tay was launched by the 1st and 2nd Brigades of the U.S. 4th Infantry Division and the ARVN 40th Infantry Regiment, 22nd Infantry Division and 52^nd Ranger Bttalion against Base Area 702 (the traditional headquarters of the PAVN B3 Front) in northeastern Cambodia from 5–25 May.