Léger's experiences in World War I had a significant effect on all of his work. Mobilized in August 1914 for service in the French army, he spent two years at the front in Argonne. He produced many sketches of artillery pieces, airplanes, and fellow soldiers while in the trenches, and painted "Soldier with a Pipe" (1916) while on furlough. In September 1916 he almost died after a mustard gas attack by the German troops at Verdun. During a period of convalescence in Villepinte he painted "The Card Players" (1917), a canvas whose robot-like, monstrous figures reflect the ambivalence of his experience of war. As he explained:... I was stunned by the sight of the breech of a 75 millimeter in the sunlight. It was the magic of light on the white metal. That's all it took for me to forget the abstract art of 1912–1913. The crudeness, variety, humor, and downright perfection of certain men around me, their precise sense of utilitarian reality and its application in the midst of the life-and-death drama we were in ... made me want to paint in slang with all its color and mobility. "The Card Players" marked the beginning of his "mechanical period" of which "Ballet Mécanique" is a part, an artistic technique that combined the dynamic abstraction of constructivism with the absurd and unruly qualities of Dada. We see this trend in the film from beginning to end.