'' ... Stratagem was , therefore , indispensable ; and it was necessary to blind Varus to their schemes until a favorable opportunity should arrive for striking a decisive blow ... '' British historian Edward Shepherd Creasy ( 1812 -- 1878 ) '' ... Stratagem was , therefore , indispensable ; and it was necessary to blind Varus to their schemes until a favorable opportunity should arrive for striking a decisive blow ... '' , British historian Edward Shepherd Creasy ( 1812-1878 )