Indonesian nationalism and militarism started to gain momentum and support in World War II during the Japanese occupation of Indonesia. To gain support from the Indonesian people in their war against the Western Allied force, Japan started to encourage and back Indonesian nationalistic movements by providing Indonesian youth with military training and weapons. On 3 October 1943, the Japanese military formed the Indonesian volunteer army called PETA ( – Defenders of the Homeland). The Japanese intended PETA to assist their forces oppose a possible invasion by the Allies. The Japanese military training for Indonesian youth originally was meant to rally the local's support for the Japanese Empire, but later it became the significant resource for the Republic of Indonesia during the Indonesian National Revolution in 1945 to 1949. Many of these men who served in PETA, both officers and NCOs alike like Soedirman, formed majority of the personnel that would compose the future armed forces.