Kammala jumla mai zuwa: A watan Fabrairun 1939, Pétillon ya nemi a tura shi zuwa Congo ta Belgium kuma ya sami matsayin "shugaban majalisar zartarwa" ga Gwamna Janar, Pierre Ryckmans. Har yanzu yana cikin Kwango a watan Mayu 1940 lokacin da Jamus ta mamaye Belgium. Duk da cewa an sanya shi a matsayin De Vleeschauwer na "shugaban majalisar zartarwa" tare da gwamnatin Belgium a gudun hijira a London, Pétillon ya shafe yawancin yakin duniya na biyu a Kwango. Bayan da
'Yanci na Belgium a watan Satumbar 1944, Pétillon ya taka muhimmiyar rawa wajen sake kulla dangantaka tsakanin gwamnatin mulkin mallaka a Afirka da Ma'aikatar Masarautar.