– by Pratyusha Mukherjee
North Bengal’s narrow piece of land – scarcely 20 kilometres wide – is the sole overland link between mainland India and its eight north-eastern states, home to over 45 million citizens. Bounded by Nepal, Bhutan, Bangladesh and China’s Chumbi Valley, the Siliguri Corridor has always carried strategic weight far beyond its modest width. That weight has grown considerably heavier over the past year, as developments in Beijing, Dhaka and along India’s own eastern frontier have converged to test – and ultimately strengthen – India’s preparedness.
Partition first created this vulnerability in 1947 and the 1962 war with China entrenched its centrality to Indian defence planning. The 2017 Doklam standoff, when Indian troops blocked a Chinese road crew from advancing toward the Bhutan-China-India tri-junction, remains the corridor’s most consequential flashpoint; satellite imagery has since confirmed a permanent Chinese military build-up near the site, a reminder that the underlying dispute is dormant, not resolved.
Recent moves of Bangladesh government’s seeking Chinese help to revive the Lalmonirhat airbase, barely a hundred kilometres from the corridor alongwith weighing of the position of handling of the Teesta river management project to a Chinese state firm are both signalling Chinese-linked infrastructure creeping closer to India’s eastern periphery.
India has responded with calibrated diplomacy rather than public rancour. Following the fall of the Awami League government in August 2024, New Delhi moved swiftly to re-establish contact, hosting Bangladesh’s first ministerial visit under the new dispensation in April 2026, when Foreign Minister Khalilur Rahman met External Affairs Minister S. Jaishankar and National Security Advisor Ajit Doval to discuss energy co-operation, border management and river-water sharing. Prime Minister Tarique Rahman’s decision to make China, not India, his first overseas stop in June 2026 tested this outreach, as did continuing friction over border pushbacks, visa curbs and the pending renewal of the Ganga Water Treaty. India’s approach has nonetheless remained one of sustained engagement – keeping institutional channels such as the Joint River Commission and Foreign Office Consultations open – even as it hedges through firmer border management and infrastructure consolidation at home.
Dhaka’s tilt has not been confined to Beijing. Since October 2024, Bangladeshi officials have resumed training exchanges with Pakistan for the first time in over a decade and senior Pakistani military figures have visited Dhaka – deepening a bureaucratic and security relationship that lay dormant through the Awami League years. Compounding this, the political vacuum since 2024 has allowed previously suppressed Islamist groups – Jamaat-e-Islami, Hefazat-e-Islam and smaller jihadist networks – to re-emerge, stage large public rallies and per Indian security assessments, begin networking with Pakistan-based groups. Rising attacks on religious minorities and hardening rhetoric have further unsettled New Delhi, which views a radicalising eastern neighbour as a direct security concern along the border. India has responded by strengthening border coordination through BSF–BGB conferences and continued inspections on fencing the borders while keeping diplomatic doors open-a dual approach designed to avoid pushing Dhaka further into Beijing’s or Islamabad’s orbit.
New Delhi has not waited for these pressures to peak. Over the past year, the Army has raised new forward garrisons around the corridor, led by the Lachit Borphukan Military Station in Assam’s Dhubri district, built for rapid deployment and persistent surveillance; the base was fast-tracked on Assam’s own request after communal tension in Dhubri as a hub for area control, counter-infiltration and technical surveillance. These garrisons sit alongside a layered air-defence shield – S-400 batteries, Akash-NG missiles, BrahMos strike systems – and Rafale fighters, with the Indian Air Force underscoring its reach through a first-ever air display in Guwahati.
India’s military readiness has also been demonstrated repeatedly time and again. The Indian Army’s completed a month-long high-altitude live-firing exercise in the Sikkim sector. Additionally a joint exercise “Trishakti Prahar” brought together the Army, Indian Air Force and Central Armed Police Forces in North Bengal, culminating in an integrated fire-power demonstration at a Field Firing Ranges near Siliguri that combined Rafale jets, attack helicopters, infantry combat vehicles and artillery in a synergised and networked battle drill. In November 2025, the Air Force additionally issued notices for a week-long exercise across the border areas facing China, Bhutan, Myanmar and Bangladesh simultaneously, testing rapid mobilisation and coordinated border-dominance drills. Top leadership of defence forces has explicitly iterated that these measures reflect standing readiness rather than reaction to any single event.
This military build-up is matched by an infrastructure push designed to make the region resilient by design. An underground rail tunnel linking Dumdangi to Bagdogra and India’s first underwater twin-tube tunnel beneath the Brahmaputra, are engineered to keep the Northeast connected even under stress. Alongside these, the Sivok Rangpo line is set to give Sikkim rail access for the first time, while the Kaladan project through Myanmar, a proposed rail link via Nepal and eventual use of Iran’s Chabahar port offer alternative routes that reduce dependence on any single passage. Rail logistics radiating from the New Jalpaiguri junction now connect the corridor directly to forward areas in Assam and Arunachal Pradesh, while arterial highways from Guwahati extend all the way to Tawang near the China border. Together, these developments are knitting together a road, rail and air network that is credited with enabling multiple formations across West Bengal, Sikkim and the Northeast to operate as a single, integrated force for both defensive and offensive contingencies.
All together, these steps reflect a deliberate reorientation: The defence corridor, is being consolidated, garrisoned and diversified into one of India’s most prepared strategic zones. The defence corridor, in coming years will test whether that consolidation, paired with patient diplomacy, can keep pace with a fast-shifting neighbourhood.
