 Giáp adopted the alias Duong Huai-nan, learned to speak and write Chinese, and studied the strategy and tactics of the Chinese Communist Party.In September 1940, Vichy France agreed to the Japanese occupation of Vietnam, to 'protect' Indochina.In May 1941 the Eighth Congress of the Indochinese Communist Party decided to form the Viet Minh; Giáp was made responsible for establishing an intelligence network and organising political bases in the far north of the country.