He was the leader of the NSCN-K, an insurgent group that operates to establish a Greater Nagaland (or Nagalim), a sovereign state bringing all Naga-inhabited areas of Myanmar and India under one administrative setup.

[6] During the War, the Western Allies built the 1,726 kilometres (1,072 mi) long Stilwell Road connecting Ledo in India's Assam to China's Kunming to carry supplies against the Japanese Army, that passed through Waktham.

They, along with another leader Isak Chishi Swu subsequently formed a partnership in revolting against the NNC for signing the Shillong Accord of 1975 that accepted the supremacy of the Indian Constitution.

[7] The NSCN became very powerful and by 1985, it was running a parallel government in Nagaland, also extending its influence to adjoining districts of the neighbouring Indian States of Manipur and Arunachal Pradesh.

In addition to insurgent and anti-establishment activity, he gave space to other separatist outfits such as United Liberation Front of Assam (ULFA) and I. K. Songbijit's faction of National Democratic Front of Bodoland (NDFB (Songbijit)), Kamtapur Liberation Organisation (KLO), Kangleipak Communist Party and Kanglei Yawol Kanna Lup to set up hideouts alongside the NSCN-K's headquarters.

He died of cardiac arrest on 9 June 2017 in Taga, in the Naga Self-Administered Zone, Sagaing Region of Myanmar, where the NSCN-K was based during the time.