The military apparatus of the Viet Minh was founded in 1944 in the retreat areas within Vietnam. The most important base area was Viet Bac in northern Tonkin near the border with China. Other base areas were located in southern Tonkin and in Annam south of Hue. In Cochinchina, the Viet Minh had only a small base of operations in the south of the Mekong Delta. Based on Mao Zedong's doctrines, the Viet Minh leadership propagated a three-phase course of war with the goal of achieving Vietnamese independence through military victory. In the first phase, Viet Minh forces were to act primarily defensively, expanding their sphere of influence only through guerrilla action. After enough regular troops had been raised and the necessary logistics for them had been created, the war was to move into a phase of "parity" in which the Viet Minh were to further expand the territory under their control in localized conventional operations. In the final phase, superior Viet Minh forces were to wrest military control of the country from the colonial power in supra-regional mobile operations.
Commander-in-Chief Võ Nguyên Giáp summarized the strategy in a post-war publication as follows:
"Only a protracted war could enable us to make perfect use of our political trump cards, to overcome our material disadvantage, and to transform our weakness into strength. [...] We must build up our strength during the course of the war."
The Viet Minh organization was formed analogously to this doctrine and included three separate troop organizations. The guerrilla forces were primarily part-time soldiers who operated close to where they lived and worked. The groups recruited from one or more villages and carried out guerrilla actions, sabotage operations, and intelligence tasks. The next level was formed by regionally organized, conventionally equipped full-time soldiers who worked closely with the guerrillas within a territory in battalion to regimental strength. At the top were regular forces equipped as light infantry, which were subordinate to the general staff and were to be deployed throughout Indochina. The Viet Minh began in September 1945 with about 31,000 regular soldiers. By the turn of 1948/1949, the regular forces had grown to 75,000. Regional and guerrilla forces provided 175,000 troops. By the end of 1954, the Viet Minh reached 161,000 regular soldiers, 68,000 regional troops, and 110,000 guerrillas.
Viet Minh forces were supported by an elaborate logistics system that ensured food and material supplies mostly through carriers. The strength of civilian logistics personnel varied from around 30,000 to 300,000 during the war.
The source of funding was the siphoning off of the rice harvest and the labor force of the areas politically controlled by the Viet Minh. The supply of the approximately 300,000 Viet Minh soldiers required the transport and distribution of about 110,000 tons of food, mainly rice. To meet the needs in the combat zone of the north, the Viet Minh imported rice on a larger scale from the predominantly pro-French southern part of the country. Through camouflage, close networking with the population and high mobility of their units and camps, the Viet Minh were mostly able to escape the grasp of the colonial forces.
In the summer of 1945, a Communist Chinese regiment retreated to Tonkin due to military pressure from the Nationalists in the Chinese Civil War. They were supported and hidden there by the Viet Minh. In return, the Viet Minh received training assistance from the Chinese exiles. In the process, about 830 soldiers and officers were trained by Chinese cadres until 1947. After the victory of the Chinese communists in the civil war, the Viet Minh received direct supplies of military and civilian material from the People's Republic of China starting in 1949. Estimates put the total at more than one hundred thousand infantry weapons and more than four thousand guns. More than nine-tenths of this material was of US manufacture and had been captured during the Civil War or the Korean War.
In order to ensure the smooth delivery of weapons and supplies, around 100,000 forced laborers built four trunk roads on the Chinese side of the border in the direction of Tonkin. Some 15,000 to 20,000 Viet Minh recruits were trained each quarter in the Chinese provinces of Yunnan and Guangxi with the help of the Chinese military, starting in 1950. Similarly, in August, the People's Republic sent a military mission of several hundred mostly senior officers under the command of General Wei Guoqing to North Vietnam. These assisted the Viet Minh at the division and high command levels as military advisors. The Soviet Union was reluctant to support the Viet Minh. Aid was delivered on a small scale from the GDR and Czechoslovakia.
In December 1945, the French ground forces in Indochina consisted almost exclusively of the 47,000-strong CEFEO expeditionary corps. By December 1946, this had grown to about 89,000 troops and was supported by 14,000 native soldiers. By the end of 1950, 87,000 Expeditionary Corps soldiers and 85,000 indigenous troops were fighting the Viet Minh. By July 1954, French forces included 313,000 indigenous soldiers and 183,000 Expeditionary Corps members.
During the war, no French government ever seriously considered the use of conscripts in Indochina, which had been called for several times by various military leaders. As a result, the Foreign Legion served as an indispensable reserve to lead the Indochina War, providing mostly the most combat-ready units of the Expeditionary Corps. During the war, a total of 78,833 legionnaires served in Indochina. To meet the CEFEO's manpower needs, massive numbers of colonial troops were seconded from North Africa to serve in Indochina. Beginning in 1948, the French military attempted to meet their manpower needs from the colony itself by recruiting locals under the catchphrase of jaunissement (German for "yellowing"). At any given time, about 60% of the combatants deployed were not French nationals. In the same year, the French government allowed those convicted of belonging to units of the Vichy regime or the Waffen-SS to receive amnesty in exchange for deployment in the Far East. From 1948 onwards, some 4,000 French prisoners enlisted.
In order to maintain the personnel strength of the Foreign Legion of just under 20,000 soldiers serving in the CEFEO, the Legion resorted to predominantly German volunteers. Their share of the deployed legionnaires rose from about 35% in the 1940s to about 55% in 1954. In many of the Legion's units stationed in Indochina, German became a lingua franca for the Legionnaires. In 1945 and 1946, up to 5,000 German prisoners of war joined the Legion, making up nearly one-third of the Legion's recruits at the time. According to official orders, members of the Waffen-SS or war criminals were to be barred from service, but this was often disregarded by the recruiting offices. The recruitment of German prisoners was controversial in both Germany and France, and in France led to public expressions of displeasure with the troops. However, the extent of prisoner recruitment was overestimated in both publics. Pierre Thoumelin even raises the question of whether German war criminals were specifically recruited from the ranks of former elite troops (e.g. paratroopers) in order to purposefully use their experience from fighting the partisans in the Balkans.
In the first phase of the war, French forces experienced a relative shortage of materiel and modern vehicles and aircraft. Against the backdrop of the escalating Cold War, the U.S. government, after initial reluctance, shifted to direct material support for French warfare beginning in 1949. This led to the French forces in Indochina as well as the national armies of the French-dependent states of Vietnam, Laos, and Cambodia, formed in 1949, being fully equipped with modern U.S. materiel. From 1950 to 1954, the United States supplied some 30,000 motor vehicles, some 360,000 firearms, 1880 tanks and armored vehicles, and some 5000 artillery pieces. The French forces likewise received 305 aircraft and 106 ships. Among these were two light aircraft carriers. During the course of the war, U.S. materiel supplies met about 70% of the French forces' needs. Among other supplies, more than 500 million rounds were delivered for infantry weapons and at least ten million for guns. The French logistics system was based on fixed depots established during the colonial period, mostly in population centers. The main burden of transport was borne by trucks. In addition, transports were also carried out by river navigation and railways. Transports by porters and pack animals took a secondary role. At all levels, French supply transports were subject to Viet Minh guerrilla attacks and sabotage. This led to a shift toward air transport via airfield or parachute drop. Helicopters were also used to a limited extent. Two separate logistical systems developed in the process. In addition to the static system used to supply troops at population centers, a rapid response system was needed to support combat troops in difficult and remote terrain.
Both sides had to contend with high desertion figures. For the Viet Minh, complete figures are not available from either the French or the Vietnamese side; estimates amount to several tens of thousands. On the French side, there were some 16,000 desertions among CEFEO troops, mainly in colonial units composed of natives. The reasons for the desertions were mostly breaches of discipline or other conflicts with the law. Political motives were in the minority. The formally independent units of the armies of the states associated with France had a higher desertion rate, with some 38,000 men deserting. More than four-fifths of the desertions occurred during the last two years of the war, 1953-1954. A few hundred soldiers defected to the Viet Minh.