The failure of the Yên Bái mutiny by Vietnamese soldiers in the French colonial army on February 10, 1930, caused the French authorities to engage in a reform of military policies which were aimed at preventing future uprisings. French trust in the Vietnamese soldiers' loyalty as colonised subjects who were simultaneously enforcers of colonial order had never been high, and the mutiny resulted in increased safeguards against Vietnamese soldiers in an attempt to prevent future incidents. Around 80% of the Vietnamese soldiers in Tonkin were transferred to other districts in order to disrupt any secret plots that may have been in progress, and some soldiers who had returned from foreign service were discharged in the fear that their overseas experiences made them less likely to accept colonial subjugation. The internal reform saw the rules for expelling Vietnamese soldiers from the army liberalised and an inquiry into military intelligence resulted in closer cooperation between military intelligence and their French colonial civilian counterparts, while French officers were ordered to improve their Vietnamese language skills. The French authorities decreed that the proportion of ethnic Vietnamese soldiers was too high and reduced the proportion of Vietnamese by replacing them with European, Cambodian, Lao and ethnic minority Montagnard people.
Military reforms precipitated by the mutiny
The mutiny refocused attention on the long term tension over the use of Indochinese soldiers, and on the ways in which it could be resolved. The tension could be traced back to the creation of French Indochina. Cochinchina, the European term for southern Vietnam, had been colonized in 1867 and the remaining parts of Vietnam, Tonkin and Annam, the northern and central regions were conquered in 1883. Nominally, only Cochinchina was a colony, while Tonkin, Annam, Cambodia and Laos were protectorates which together comprised French Indochina. The problem centred around the French reliance on native soldiers to maintain colonial control. This need was problematic because Indo-Chinese soldiers were both enforcers of colonial order and colonial subjects. This created constant French concerns about their loyalty. Despite several attempts to deal with the issue, the basic tension between the need for and suspicion of native troops could never be entirely resolved. The need for forces to pacify the countryside was too pressing to do without them. As a result, the tension resurfaced at regular intervals, either due to proposals to improve the position of Indochinese soldiers in the army, or after a mutiny had raised question marks about the loyalty of the soldiers.
Background of Vietnamese troops in the French colonial army
The demand for Indochinese soldiers, auxiliaries first, and then regular troops, had been present since the beginning of the French conquest. French troops were never numerically sufficient to assert control of the populace and then maintain Pax Gallica in the colony, thus requiring local reinforcements. Home grown French troops were lacking because they were too expensive for Paris and Hanoi, in contrast to the substantially cheaper native troops. A lack of manpower back in Europe caused by other imperial programs and the demographic trough caused by mass casualties in World War I on the Western Front further caused a need for the recruitment of Indochinese troops. Because French Indochina was a domination and exploitation colony rather than a settler colony, the pool of local Frenchmen was far too small to build a settler-army.Rettig, p. 312. Native troops generally knew the land and people much better, could be used in terrain on which foreign troops were disadvantaged. They were far more abundant than French born troops, whose deployment to Indochina was time-consuming, expensive and risky. Aside from the risks associated with the closure of sea lanes, the emergency dispatch of metropolitan troops from Paris could not be taken for granted. Particularly after 1915, French Indochina was expected to financially contribute to the defence of the colony and even to send native troops to France.Rettig, p. 313.
The native soldiers fulfilled a number of different purposes. Initially they were collaborators in the conquest of Indochina, helping to defeat the forces of the Nguyễn dynasty and then in its pacification. After the pacification campaign was officially completed in 1897, the two main functions of the colonial army were the maintenance of internal peace and external security. Both these tasks were fulfilled in conjunction with other armed institutions, such as the Garde indigène (later indochinoise), the Gendarmerie, the police, and the partisans in the border regions. The Garde indigène, a paramilitary force, was primarily responsible for dealing with disturbances of the peace and thus played an important role in the repression of public demonstrations and popular unrest.
In the areas bordering China, the military had a much more active role in securing the frontier against incursions by smugglers, bandits, and politically motivated militants.
The participation of native soldiers in the colonial forces was used as political symbolism, proof that the Union's five territories were rightfully under French tutelage, as evidenced by the populace's contribution of soldiers to a common army under French command. This was the "blood toll" to be paid for the Pax Gallica. In their position as colonizers and colonial subjects, the native colonial troops were also buffers between the French and the unarmed populace. Their sheer presence demonstrated French control and power to the ordinary population, posing a considerable obstacle to those who intended to overthrow French rule using violence.Rettig, p. 314.
The dilemma was that the French needed local soldiers to maintain the Union's internal and external peace, but could not rely on them too deeply because of an innate distrust. French concerns about disloyalty resulted from a fear that the colonialised soldiers would turn their weapons on their masters, or desert them in an emergency situation. Such fears were deeply institutionalised in the army in the form of "safe" ratios of "white" and "yellow" soldiers, the segregation of the army into its various Indochinese constituencies, and the establishment of racialised access to command hierarchies that excluded natives from becoming officers until 1929. The mutiny triggered the long existing fears about the loyalty of native soldiers, as well as many traditional French responses.
Transfer of soldiers
In addition to the individual military punishments, the army took further internal measures to lower the risk of another insurrection. According to Maurice Rives, 10,000 Vietnamese troops were given transfers to different zones. This meant that more than 80% of Tonkin's approximately 12,000 Tirailleurs Tonkinois (Tonkinese Rifles) were moved,Rettig, p. 317. a transfer of enormous proportions, indicating the extent of insecurity among French commanders towards Vietnamese troops, and the extent to which they were willing to go to make future Yên Báis impossible. One possible rationale for this measure was to break up any undiscovered VNQDD cells and to sever personal ties, within units and between soldiers and civilians in their local district. The mass transfer of soldiers also had the effect of creating a state of constant mobilisation, denying troops the time and opportunity for anti-colonial organisation. In the words of a French officer who wrote in his diary under the pseudonym Bôn Mat, the measures would also force French officers to be more watchful, as "[t]roops which do not work sufficiently and which are not looked after properly, lose their spirit of discipline; or rather, unoccupied troops cannot be disciplined."Rettig, p. 318.
Aside from measures in Vietnam, 2,000 Indochinese soldiers returning from service in France were sent on indefinite leave and were not replaced with new recruits from Vietnam. The reason is put down by historians to be because military discipline in France was less regimented than in Indochina and other colonial garrisons. In colonial units, the colonial military and social order with Frenchmen above their indigenous troops was more easily reproduced. The French home services lacked officers specialising in commanding colonial troops; this was one of the main reasons of the disorder, as they unlike their colleagues posted to the colonies, did not know how to lead Vietnamese soldiers. Metropolitan officers also treated their Vietnamese subordinates on a more equitable basis, thereby subverting the colonial hierarchy of racial inequality under which the Vietnamese had been trained. As an example, Indochinese warrant officers had the right to command and be saluted in the metropolitan services, whereas in Vietnam only French soldiers had such rights.
Away from the discipline and the colonial hierarchy they were used to, the Vietnamese soldiers could become so alienated with their experiences that they became soft targets for communist propaganda. Upon returning home to Vietnam, they attempt to indoctrinate other troops with their Marxist doctrine. This train of thought further reinforced French perception that subversive ideas came from the outside rather than domestically: of the 57 soldiers involved in the mutiny, 17 had served abroad. On the other hand, according to the Thiry report, the proportion of soldiers with foreign service at Yên Bái did not exceed that in other garrisons, so this was not abnormal.Rettig, p. 319.
Military intelligence reforms
In addition to punishing soldiers, tightening dismissal regulations and reducing the number of Vietnamese servicemen in France, the French decided to improve the military intelligence service. This was to be achieved by strengthening military intelligence through closer coordination with the Sûreté, and by raising internal standards.Rettig, p. 320. In terms of coordination, an inquiry into the mutiny at Yên Bái showed that cooperation between Resident Massimi and Commandant Le Tacon did not exist despite multiple requests, and that this was partly responsible for the failure to prevent the uprising. Although the relationship between the civilian authorities in Tonkin and the military were traditionally marked by rivalry, Yên Bái stood out in the total lack of military–civilian cooperation. Further VNQDD conspiracies to foment mutinies in other garrisons, such as Kien An, were detected and scotched at late notice. Although the performance of the intelligence service was regarded as being substandard at Yên Bái, the army command in Vietnam realised, under criticism from civil authorities who claimed they had not been sufficiently cooperative in the past, that the teamwork with the Sûreté had to be raised to greater heights to prevent future Yên Bái style rebellions. For such reasons, Patrice Morlat wrote that the mutiny at Yên Bái allowed the Sûreté to "penetrate indirectly into the military sector which had till then been inaccessible".Rettig, pp. 320–321.