After the German invasion of the USSR, Kušal worked as director of a training school for the Belarusian Auxiliary Police, then worked at various leading positions of the local Belarusian self-defence and police units and organising training for Belarusian officers. In 1943, Kušal became member of the Belarusian Central Rada, responsible for military issues. Since March 1944, he was head of the Belarusian Home Defence (BKA) - a 25 thousand to 50 thousand men strong Belarusian army, for the creation of which the Belarusians have received German approval at the final stage of the war.