Following major defeats in the northern delta in 1951, the Democratic Republic of Vietnam’s (DRV) High Command began work to push a strategic route southwards along the hilly western periphery of the delta in order to supply central and southern zones. Controlling Hoa Binh and areas along the Black River was crucial to the extension of this trans-Indochinese route. The DRV had retaken Hoa Binh in 1950, turning it into a major interchange in its logistics and communications with the rest of Indochina. The French were not dupes, however: in November 1951, General Jean de Lattre de Tassigny recovered Hoa Binh in order to thwart the development of just such an Indochinese supply route, to prevent the DRV from infiltrating troops into the delta via the south, to reassure minority ethnic groups in Hoa Binh of French resolve, and to demonstrate the French will to take on the Vietnamese, especially to the Americans and the emerging Associated State of Vietnam.
General Vo Nguyen Giap was determined to take it back and saw an advantage in attacking the French posts there given the craggy, mountainous terrain (similar to the terrain he exploited successfully during the Cao Bang battle). On 10 December 1951, Vo Nguyen Giap sent battle-hardened elements of the 304th, 308th, 312th, and 351st against French positions. Attacking at night in order to avoid the full brunt of French airpower, Giap threw waves of men against the French Union forces in a bid to encircle, overwhelm, and destroy the camp. The French had five infantry battalions, an artillery group, and mobile groups waiting for them and paratroopers were already harassing Vo Nguyen Giap’s lines of communications. Fighting at Hoa Binh was intense, with French artillery inflicting heavy losses on the DRV’s troops attempting frontal assaults. During the battle, the French Air Force lost its first plane to the adversary’s still rudimentary but operational anti-aircraft battery as the DRV’s troops expanded their control in the Hoa Binh–Black River area. On 22–23 February, as the Vietnamese massed for a final knock-out punch, General Raoul Salan decided to pull his troops out of Hoa Binh, preventing Giap from scoring the decisive victory he wanted.
The battle cost the lives of some 10,000 killed and wounded for the DRV and about a 1,000 for the Expeditionary Corps. Although neither side scored a clear victory, it was clear from this point that the DRV’s army was operating in a modern fashion, that its commanders were quite capable of coordinating and operating a battle over a large area, and that they were keen on taking the battle to the French using Chinese-inspired wave tactics. By taking Hoa Binh, the DRV also began work pushing an overland Ho Chi Minh Trail southwards to supply Inter-Zone V (Lien Khu V) and lower Indochina. As Yves Gras aptly summed up the significance of the battle: “The truth is that the Viet Minh, very fluid and mobile, was moving with great speed and knew how to concentrate its efforts at the opportune moment”. The problem for the Vietnamese high command, however, was that the French were very good at pulling out their forces, thereby denying Vo Nguyen Giap a decisive victory he increasingly had to score.