Operation Attleboro was a Vietnam War search and destroy operation initiated by the 196th Light Infantry Brigade with the objective to discover the location(s) of People's Army of Vietnam (PAVN) and Viet Cong (VC) base areas and force them to fight. The operation was named after Attleboro, Massachusetts, where the brigade had been formed. Operation Attleboro grew to be the largest series of air mobile operations to that time, involving all or elements of the 196th Brigade, 25th Infantry Division, 1st Infantry Division and a brigade of the 4th Infantry Division, as well as numerous Army of the Republic of Vietnam and Regional Forces/Popular Forces and Nùngs. In the end, the operation became a Corps operation commanded by II Field Force, Vietnam.
Background
In late 1966 interdiction remained a high priority for US forces, and, until the dry season began in earnest, COMUSMACV General William Westmoreland's primary concern remained blocking the three infiltration corridors into Saigon.
Senior Colonel Hoàng Cầm, commander of the 9th Division, had his orders: "destroy a 'vital' element of the enemy, support the local [revolutionary] movement, oppose enemy pacification and expansion effort, break the oppressive government control, widen friendly liberated areas, and provide security and protection for storage facilities and base areas of Dung Minh Chau [War Zone C]." This was standard operating procedure for a dry season offensive, but in late 1966 the 9th Division was weakened by heavy losses that the previous summer 's combat had inflicted. Despite this, General Nguyễn Chí Thanh, the COSVN commander, decided to use the 9th, his most reliable and experienced, for a November offensive in Tây Ninh Province. His guidance to Cầm was to direct his "main effort" on the inexperienced 196th Brigade, just settling in at Tây Ninh, and local territorial and Civilian Irregular Defense Group (CIDG) units. Cam planned to open the offensive on 3 November with three regiment-sized attacks. First, he assigned the 271st Regiment, a unit of about 1,500 men, to strike the 196th's base at Tây Ninh Combat Base and attempt to lure and annihilate any of the brigade's reaction forces. His 272nd Regiment with two battalions was to move south across the Saigon River and join the 14th Local Force Battalion, the provincial VC unit for Tây Ninh Province, to attack South Vietnamese territorial outposts at Suoi Cao, thirty kilometers southeast of Tây Ninh City. The remaining battalion of the 272nd was to join the 101st Regiment, a unit of the 7th Division on loan to Cầm, for the third and main effort, the destruction of a Special Forces camp at Suoi Da, 15 km northeast of Tây Ninh City. For this mission Cầm provided to the 101st an antiaircraft and a mortar company from his own division. In all, the reinforced regiment would have about 3,000 troops. Cầm himself intended to accompany the 101st Regiment, a unit that had seen little combat and was unfamiliar with the terrain of War Zone C, to its forward assembly areas near Suoi Da and then to depart to occupy a central position from winch to coordinate all three assaults.
The 196th Brigade, a relatively green unit, had arrived in South Vietnam less than two months earlier, on 14 August 1966. The brigade deployed immediately to Tây Ninh, coming under the operational control of the Major General Frederick C. Weyand's 25th Infantry Division. Shortly afterwards Brigadier General Edward H. de Saussure assumed command of the Brigade. De Saussure was considered by many a superb staff officer and an authority on missiles, but he had no experience commanding infantry. He did have proven ability with artillery units and before joining the 196th had served fifteen months as the assistant division commander for support in the 25th Division, four months of that time in Vietnam.