Unlike Pétain, de Gaulle believed in the use of tanks and rapid maneuvers rather than trench warfare. De Gaulle became a disciple of Émile Mayer (1851–1938), a retired lieutenant-colonel (his career had been damaged by the Dreyfus Affair) and military thinker. Mayer thought that although wars were still bound to happen, it was "obsolete" for civilised countries to threaten or wage war on one another as they had in previous centuries. He had a low opinion of the quality of French generals, and was a critic of the Maginot Line and a proponent of mechanised warfare. Lacouture suggests that Mayer focused de Gaulle's thoughts away from his obsession with the mystique of the strong leader ("Le Fil d'Epée": 1932) and back to loyalty to Republican institutions and military reform.