At the end of the Second World War, the medical infrastructure of the French army – profoundly disorganised by the defeat of 1940 – had to be rebuilt. A key site for reform was resuscitation and blood transfusion, which was put to the test in 1946 by the Indochina War. For blood transfusion, the stakes were high since it required the integration of numerous scientific, technical, and organisational innovations developed during previous 20th-century conflicts. This talk will analyse to what extent the (re)founding of the transfusion capacities of the French army, as tested during the Indochina War, were shaped by the scientific, medical, and military contexts of French medical services, and to what extent shaped through a close dialogue with American experts and institutions.