Ndalla was associated with opposition leader Bernard Kolélas and his party, the Congolese Movement for Democracy and Integral Development (MCDDI), during the 1990s, and he helped to recruit fighters for the Ninja militia loyal to Kolélas. During the June–October 1997 civil war, Ndalla objected to the MCDDI's moves toward an alliance with President Pascal Lissouba and defected to the side of Denis Sassou Nguesso and his rebel Cobra militia.