Shortly after the murders, Vandewalle officially became the commander of the Katangese Gendarmerie, the security forces, probably to prevent that the French mercenary Roger Trinquier would take up that position.

In 1964, Tshombe returned from exile in Francoist Spain to become the prime minister of the reunified Congo under president Joseph Kasa-Vubu.

The Congolese National Army (Armée nationale congolaise, ANC) could not control the security situation in the country, particularly with regard to the Simba rebellion in the east.

[3] He received the order on 28 August to reconquer the rebellious region (with the approval of general Joseph-Désiré Mobutu) and could make use of foreign troops, including Cuban exiles sponsored by the Central Intelligence Agency (CIA) and Belgian military staff, and the approximately 350 white mercenaries of Mike Hoare.

He also appeared on television: RTBF-journalist Henri-François Van Aal [fr] dedicated an episode of Télé-mémoires congolaises to an interview with him (1970).

[4] Vandewalle wrote his memoirs Mille et quatre jours about the Katangese period down in 13 fascicles, published in small numbers.

According to Ludo De Witte, the memoirs exhibit great candidness because they are written at a time of neocolonial victory feeling.