Naga areas were totally isolated during British rule and after Independence, government of India sought to integrate them, but they opposed in favor of a separate independent state under leadership of A Phizo and British officers and missionaries support. In 1955, a violent campaign was launched by Nagas and they declared independence from Assam and India. To this government of India responded with a firm foot and sent army and prolonged negotiations were also pursued along with. After army intervention, rebellions back was broken and more moderate leader Dr Imkongliba accepted the offer of separate Naga state which came into existence in 1963. Declaration of separate state led to decline of insurgency which saw sporadic outbursts with Chinese, East Pakistani and Burmese support. Army also gained some unpopularity due to some unpleasant incidents.
A few years later, similar situation developed in autonomous district of Mizo in Assam. They were relatively settled with the idea of being part of India, but inadequate measures during 1959 famine and later declaration of Assamese as official language stoked the secessionist tendencies and Mizo National Front (MNF) was formed with Laldenga as its leader and tacit support from China and East Pakistan. It declared independence in 1966 and launched violent insurgency which was met by tough stance of Indian army. Ladenga and others fled into East Pakistan and Mizoram was given status of a UT in 1973. In 1986, when MNF and Laldenga surrendered, government also softened its stance and invited them into mainstream announcing full statehood to Mizoram with Laldenga as its first chief minister in 1987.