The Achingmori incident refers to an event in the year 1953 when a group of Daphla tribals of the Tagin people killed 47 members of an Indian government party including personnel of the Assam Rifles and tribal porters during an administrative tour in Achingmori in present-day Arunachal Pradesh.
Apart from tribal rivalries and unfollowed security protocols, the massacre was also attributed to a rumour that the government party was there to free slaves.
In 1953 Nehru stated in the parliament that "The fact that that place is not an administered area does not mean that it is outside — I am not talking about law, but of practice — the territory of the Indian Union.
In 1951, India, represented by an Assistant Political Officer, Ralengnao Khathing, took control of Tawang with just one platoon (36 soldiers), of the Assam Rifles, a paramilitary force.
Singh, accompanied by 22 personnel of the Assam Rifles, one Area Superintendent, two Jamadars, two interpreters, 17 village headmen and 100 porters, arrived at Achingmori.
The location had temporary huts, and Major Singh considered this as a sign of friendliness, resulting in lax protective measures.
The atmosphere appeared so friendly that the jawans stacked their weapons some distance away from where they were distributing salt and were completely unarmed.
When the information reached Shillong, various outposts in Subansiri and the Abor Hills were reinforced with Assam Rifles platoons flown in by the Indian Air Force.
[9] On 21 November 1953, Nehru said in the parliament,[10] It would have been easy enough for us to take punitive action... We could have bombed their villages and killed a large number of their people.
We shall certainly restore peace and order in this area, bring to book the real offenders and ring leaders, but we do not wish to punish the innocent and the misguided.
What may be a criminal intent in one place in a fully administered area, in my opinion need not be so in a very remote tribal area.A large part of the restraint shown by India following this incident goes to Nari Rustomji, an advisor of the governor of Assam J D Daulatram.
[12] In place of an aggressive military reaction, Nari Rustomji got the guilty convicted after a procedurally sound trial.
[3] However, Ajai Shukla writes that the lack of Indian military in the area caused its own problems; "placing local sensibilities above national security also created the mindset that led to the 1962 defeat.