Battle of the Iron Triangle ending a bitter four-month struggle. Following the withdrawal from Base 82 COSVN organized a new corps headquarters in the Tay Ninh- Binh Long region and designated it the 301st Corps. This corps would soon direct the combat operations of the 7th and 9th NVA Divisions, separate regiments, and additional formations already en route from North Vietnam. Meanwhile General Thuần decided to rest the tired troops of the 5th Division and turned his attention to sending his 25th Division to clear out the PAVN bases in the Ho Bo area west of the Iron Triangle. The ARVN defenses around An Dien
Battle of the Iron Triangle especially in the northern part, were thick with elephant grass, higher than a man's head. The surface was scarred by countless bomb and shell craters so that vehicular movement off the narrow, rough dirt roads was nearly impossible; even tracked vehicles had difficulty. A vast network of tunnels and trenches, most of them caved-in and abandoned, laced this ground that had been the scene of battles since the First Indochina War. A weak string of three ARVN outposts protected the northern edge of the Triangle, from Rach Bap () on the west, close by the Saigon River, along local Route