At 4 AM on March 15, while the battle was raging, French General De Castries convened an urgent meeting at the headquarters bunker to discuss ways to salvage the situation. Langlais suggested using the 5th Parachute Battalion (with an additional company of the 1st Parachute Battalion and one tank company) to conduct a counterattack. At 5:30 AM, tanks led the counterattack with paratrooper units following behind. When the French troops reached the southern slope of Doc Lap Hill, the sky was bright. The fighting was very fierce. By 7:30 AM, all tanks and paratroopers had fled back to Muong Thanh. The counterattack against the French troops ended successfully. In the battle of Doc Lap Hill, the Vietnamese troops killed nearly 500 enemies and captured 200 others, including two battalion commanders (both former and incumbent commanders).
In coordination with the Dien Bien Phu battlefield, on March 15, the Inter-Region Command 4 instructed Binh-Tri-Thien region to actively conduct strong attacks on traffic roads and prevent raids and conscription. As a result, the Inter-Region Special Forces destroyed six enemy’s positions and 12 bunkers. The special propaganda movements to deal with enemies also attracted the participation of a large number of people. In Hue, the Vietnamese side distributed tens of thousands of leaflets, wrote thousands of slogans, established 80 propaganda loudspeaker groups, and sent hundreds of letters to puppet officers and soldiers, calling on them to abandon the French troops to return to the Vietnamese resistance.
In the Northern Delta, the Vietnamese side ambushed, burned, and sank two boats and one canoe, destroying a company of marines in Yen Lenh, the Red River.
