Decker was a disciple of Isaac Wallace-Johnson's West African Youth League, which had a strong anti-colonial message and who fought for equality and independence of Sierra Leone and its citizens.
Decker foi membro da West African Youth League fundada por Isaac Wallace-Johnson en 1935, e que tiña unha forte mensaxe anticolonialista, loitando pola igualdade e indenpendencia de Serra Leoa e os seus cidadáns.