Decorated veteran of World War I and a radical socialist, Bollaert distinguished himself again during World War II when, as a deputy of the Third Republic, he refused to vote full powers to Philippe Pétain in 1940 and joined the resistance. In September 1943, Bollaert replaced Jean Moulin as general delegate to occupied France for the French Committee for National Liberation (Comité français de Libération nationale). Arrested by the Gestapo in February 1944, he was deported to Buchenwald, Dora, and finally Bergen-Belsen, from which the British army liberated him on 15 April 1945. After the war, he became commissioner for the Republic in Strasbourg before being sent to Indochina to replace Georges Thierry d’Argenlieu as high commissioner for Indochina in March 1947. Bollaert refused to exclude the possibility of resuming contact with Ho Chi Minh, and for a long time refrained from following up the contacts initiatied by d’Argenlieu’s principal advisor Léon Pignon with the ex-Emperor Bao Dai in Hong Kong. Bollaert dispatched Paul Mus to lay down the government’s conditions to Ho Chi Minh in May 1947. To no avail. In the autumn of 1947, as France launched Operation Lea in a bid to wipe out the Democratic Republic of Vietnam, Bollaert resumed work on the Bao Dai Solution, holding a highly publicized meeting with the former Emperor in Ha Long Bay at the end of the year. Following a failed attempt on his life in March 1948, Bollaert was replaced by Léon Pignon in the fall of 1948.