In 1931, during the first half of the civil war, Mao had been able to gain mass support from peasants in Jiangxi, along with a fortified military base and a battle-hardened militia. Mao was one of the few communist leaders that was capable of being an effective military commander, being able to utilize guerrilla tactics against the GMD forces and repel advancing forces into Jiangxi. However, in 1934, Chaing Kai-Shek would launch a fifth extermination campaign into Jiangxi.