Together with two other soldiers of fortune and machine gun experts, Tracy Richardson and Emil Lewis Holmdahl, Dreben's wanderings then took him to Central America. He worked as a security guard in the Panama Canal Zone. After several unsuccessful business ventures, he was recruited to fight for various liberation movements in Guatemala, Honduras, Nicaragua, and Mexico. It was in Guatemala that he suffered his only combat wound – a shot in the rear. In the Mexican Revolution, Dreben joined the forces of Francisco Madero as a machine gunner. After Madero's murder in 1913, Dreben worked for Felix A. Sommerfeld in El Paso, smuggled arms to Pancho Villa's forces, and went on sabotage missions in Mexico for Sommerfeld's secret service. When the latter made his infamous raid on Columbus, New Mexico on March 9, 1916, killing some civilians, Dreben joined the Punitive Expedition sent by an outraged America to bring his former comrade-in-arms to justice. Dreben served as a scout and became good friends with the expedition's commander, General John Pershing. The Americans were never able to catch the elusive Villa, and the fiasco eventually came to an end in 1917.