Operation Union II was a search and destroy mission in the Quế Sơn Valley carried out by the 5th Marine Regiment. Launched on 26 May 1967 the operation ended on 5 June. U.S. reported the People's Army of Vietnam (PAVN) lost 701 killed and 23 captured, while U.S. casualties were 110 killed and 241 wounded.

Background

The Quế Sơn Valley is located along the border of Quảng Nam and Quảng Tín Provinces. During the Vietnam War it lay in the southern part of South Vietnam's I Corps. Populous and rice-rich, the valley was viewed as one of the keys to controlling South Vietnam's five northern provinces by the North Vietnamese and by early 1967 at least two regiments of the PAVN 2nd Division had been infiltrated into the area. The Quế Sơn Valley was also recognized as strategically important by the U.S. Military Assistance Command, Vietnam (MACV). The 1st Battalion, 5th Marines and 3rd Battalion, 5th Marines, experienced units, that had fought in South Vietnam since their arrival in the summer of 1966, were assigned to the valley in 1967 to support the outnumbered the Army of the Republic of Vietnam (ARVN) forces in the area.

During Operation Union from 21 April to 16 May, the 3rd Battalion, 1st Marines had fought the PAVN 21st Regiment near the Marine outpost on Loc Son Mountain for control of the southern part of the Quế Sơn Valley. Operation Union II was launched on 26 May to destroy the withdrawing remnants of the PAVN with a helicopter assault by the 5th Marine Regiment, commanded by Colonel Kenneth J. Houghton. The assault was coordinated with ground attacks by the ARVN 6th Regiment, 2nd Division and the 1st Ranger Group.

Prelude

The plan called for 1/5 Marines, commanded by Lieutenant Colonel Hilgartner, to establish blocking positions in the western portion of the valley while the 3/5 Marines, commanded by Lieutenant Colonel Esslinger, was to make a heliborne assault into the southern part of the valley and sweep northeast. Meanwhile, the three battalions of the ARVN Ranger Group would attack southwest from Thang Binh, while two units of the 6th Regiment attacked northwest from a position near Tam Kỳ. The ARVN named their participation Operation Lien Ket 106.

Operation

thumb|right|5th Marines cross rice paddies in search of enemy snipers

The operation began the morning of 26 May with the 1/5 Marines and ARVN troop movements proceeding as planned. 3/5 Marines, composed of three infantry companies, one weapons company and a command group, was carried by helicopters to Landing Zone (LZ) Eagle (), an area 5 km east of the Loc Son outpost. The first two waves to arrive at the LZ experienced only light small arms fire, but as the bulk of the battalion landed the LZ was subjected to heavy weapon and mortar fire. At 11:34 the enemy defenders shot down a CH-46A Sea Knight over the LZ. An attack by Companies L and M launched to relieve the pressure on the LZ found a well-entrenched PAVN force, identified as being elements of the PAVN 3rd Regiment, northeast of the LZ.

At 14:20 Houghton called for the commitment of the 1st Marine Division's Reserve "Bald Eagle Reactionary Force", a battalion sized reactionary force unit made up of Company E, 2nd Battalion, 5th Marines; Company D, 1st Battalion, 7th Marines; and Company E, 2nd Battalion, 7th Marines and commanded by Lt. Col. Mallett C. Jackson Jr., the Battalion Commander of 2/5 Marines. At 19:00, in total darkness, Companies E, 2/5 Marines and D, 1/7 Marines were inserted by helicopter northeast of the fortified enemy positions and quickly moved south to engage the PAVN's left flank positions in order to relieve battle pressure on the 5th Marine, that were now pinned down by a large entrenched PAVN force The 2 companies quickly moved forward but were soon hit with heavy automatic weapons fire and heavy barrages of large 82 mm high explosive mortar rounds. Company D, 1/7 Marines had taken many casualties and they radioed requests for Medevac choppers, but all requests were denied because of the extreme darkness. However a CH-53 helicopter that had just dropped off the Company E, 2/7 Marines at the original landing zone heard the desperate call and was guided in to the landing zone directly in the middle of the battlefield. When the helicopter returned to Da Nang Air Base, it was noted that it had received a total of 57 holes in its sides from the exploding mortar rounds and automatic weapons fire during the battlefield landing. The sudden presence of the strong Division Reactionary Force on its northern flank caused the PAVN units to disengage and make a hasty withdrawal to the southwest, but the move proved costly to them. Once the PAVN soldiers left the protection of their fortifications, they were easy targets for the Marines supporting arms fire.

References

  • Third Battalion, Fifth Marines Official Website - Veterans' memoirs
  • Debbe Reynolds' Memorial Page - Many contemporary photos and military documents