CHAPTER X

Phase I-The Horseshoe Is Pitched

Phase I of Operation JUNCTION CITY was conducted from 22 February to 17 March and involved forces of the U.S. 1st and 25th Infantry Divisions and some South Vietnamese forces deployed in the shape of a giant horseshoe. 1st Division elements constituted the east and north portion of the inverted U; the 25th was assigned the northwestern and western portions and the mission of driving a force north through the open end. With a perimeter of approximately sixty kilometers, the western leg of the horseshoe extended north of Tay Ninh along Route 22 (with major concentration north of Route 247) to the junction at Route 246 on the Cambodian border. The top of the horseshoe was generally delineated by Route 246 (which in that area was nothing more than a cart trail) parallel to the Cambodian border on the north. The east portion continued along Route 246 to the vicinity of Katum and from there south along Route 4 to south of Prek Klok. It was through the southern opening of the horseshoe that 25th Division forces initiated their drive north to conduct search and destroy operations. To the west, south, and east of the horseshoe sweep operations were to be conducted by the units forming it. (Map 11)

The controlling headquarters for Junction City was II Field Force, Vietnam, under General Seaman. For the first time in the war, II Field Force headquarters displaced to the field and opened a tactical command post at Dau Tieng on D-day.

Combat Forces

During Phase I of Operation JUNCTION CITY the Big Red One, commanded by Major General John H. Hay, Jr., employed two of its three organic brigades (the other remained active on Revolu-tionary Development operations) and was augmented by the 173d Airborne Brigade and two South Vietnamese units named Task Force WALLACE the 35th Ranger Battalion and one troop from the ad Battalion, 1st Cavalry Regiment. Later in Phase I the 1st Bri-gade, 9th U.S. Infantry Division, joined the 1st Division to keep Route 13 open from Lai Khe to Quan Loi. The division's missions