Why Is Assam-Arunachal Border Still A Flashpoint Despite Years Of Talks

Three years after Assam and Arunachal Pradesh signed what was billed as a historic settlement of their border dispute, villagers on the two sides are fighting again. On August 10, 2026, a confrontation over alleged land encroachment at Mingmang Basti in Assam's Dhemaji district turned violent, injuring at least 11 people from Assam, with police firing reported at the scene. A fresh clash flared in the same district on August 13, once again forcing police from the neighbouring state to fire in the air to control the crowd.

The violence is a reminder that the 2023 memorandum meant to close a five-decade-old dispute settled far less than it appeared to. To understand why the border keeps reigniting, it helps to separate what was actually agreed from what continues to be contested on the ground.

What triggered the latest clash?

According to media reports, the immediate flashpoint was a dispute over alleged encroachment by residents of Arunachal Pradesh on land claimed by Assam at Mingmang Basti, in the Gogamukh revenue circle of Dhemaji district, on August 10. At least 11 people from Assam were injured in the confrontation, with several referred to Assam Medical College in Dibrugarh for treatment.

Assam Chief Minister Himanta Biswa Sarma said the situation was under control and being "resolved amicably." That reassurance did not hold: a second clash broke out in Dhemaji on August 13, again over encroachment allegations, and police had to fire in the air to disperse the crowd.

Why do Assam and Arunachal Pradesh dispute their boundary?

Assam and Arunachal Pradesh share an 804.1-km border running through Udalguri, Sonitpur, Biswanath, Lakhimpur, Dhemaji, Tinsukia, Dibrugarh and Charaideo districts of Assam, and 12 adjoining districts of Arunachal Pradesh. The roots of the dispute go back to 1873, when the British introduced an inner-line regulation that vaguely separated the plains from the frontier hills, later designated the North-East Frontier Tracts in 1915.

Arunachal Pradesh's central grievance is that forested plains tracts historically belonging to hill tribal chiefs and communities were unilaterally folded into Assam under that colonial-era line. After Arunachal Pradesh gained statehood in 1987, a tripartite committee recommended that some of those territories be transferred back; Assam contested the recommendation, and the matter remains before the Supreme Court.

How old is the dispute?

The dispute has simmered for more than five decades, since Arunachal Pradesh's creation as a Union Territory in 1972. On December 26, 2007, Arunachal Pradesh formally listed 123 disputed villages before a local commission, a list that has anchored every subsequent round of negotiation.

Along the length of the border, the two states have identified around 1,200 individual points of dispute, and the friction has periodically turned deadly — including a June 2023 shooting in Dhemaji, barely weeks after that year's landmark agreement, in which one person from Assam was killed and another injured.

What did the 2023 agreement settle?

The path to the 2023 settlement began with the Namsai Declaration of July 15, 2022, in which Chief Ministers Himanta Biswa Sarma and Pema Khandu agreed to narrow the list of disputed villages from 123 to 86, reaching consensus on the other 37 — 28 of which would stay with Arunachal Pradesh and three with Assam.

Twelve regional committees, one for each pair of districts, then carried out joint verification of the remaining villages. On April 20, 2023, the two chief ministers signed a formal MoU in New Delhi, in the presence of Union Home Minister Amit Shah, declaring it the full and final settlement of all 123 originally listed villages, with no new claims to be added.

Six villages were earmarked for realignment to separate Assamese and Arunachali habitations, and some land parcels, including Torajan Adi and Balisori, changed hands under an "as is, where is" formula.

Why do disputes continue despite the agreement?

The 2023 MoU addressed the 123 villages named in 2007, but Sarma himself acknowledged soon after that on-the-ground demarcation had not been completed in several Dhemaji-side areas, which is precisely where the fatal 2023 shooting and the fresh 2026 clashes both occurred. Local opposition also complicated implementation: the Tirap, Changlang and Longding People's Forum in Arunachal Pradesh said the MoU worked against local interests, and residents of at least 13 villages on either side objected that the ground surveys had ignored their input.

Boundary-pillar construction was still under way as recently as March 2026, when Khandu said Arunachal Pradesh had registered a net territorial gain from the process — a framing unlikely to reassure Assamese communities near the line.

Why are local land and encroachment claims so sensitive?

For border villagers, these disputes are not abstract cartography — they are questions of who can farm which field and whose home falls on which side of a line. The 2023 settlement covered a defined list of villages, but encroachment claims have continued to surface outside that list altogether: Assam told its Assembly on July 29, 2026, that Arunachal Pradesh has encroached on 16,144.01 hectares of Assamese land, of which Arunachal Pradesh is separately claiming 858.91 sq km as its own.

Differing land-tenure traditions between Arunachal's hill communities and Assam's plains settlements add another layer of friction, since a boundary agreed at the state level does not automatically settle competing customary claims at the village level.

Can the two states finally resolve the remaining disputes?

There are reasons for cautious optimism, poltical observers say that since both states are governed by the BJP, dispute resolution could prove to be slightly easier. This political alignment facilitated the 2022 and 2023 agreements and continues to support incremental progress, including the boundary-pillar work reported in early 2026. Twelve regional committees remain in place to handle outstanding issues district by district.

But the structural obstacles are real — the Supreme Court case over the original tripartite committee recommendations is still pending, local civil society groups on both sides remain unconvinced the settlement reflects their interests, and Assam's own admission of over 16,000 hectares of unresolved encroachment shows the dispute extends well beyond the villages the 2023 MoU actually covered. This week's twin clashes in Dhemaji suggest that political agreements signed in New Delhi and Namsai have yet to translate into settled facts on the ground for the communities who live along the line.