India ramps up defence as Bangladesh–China threat grows around Siliguri corridor

From caution to consolidation is New Delhi’s new defence strategy around the Siliguri Corridor, the narrow “chicken-neck” land strip connecting mainland India to the Northeast, in response to what it sees as a growing converging threat from Bangladesh and China, security sources claimed.

A high-level, multi-agency review held in Siliguri on November 22, convened under the aegis of the Intelligence Bureau’s Subsidiary Multi-Agency Centre (SMAC), and attended by the BSF, SSB, ITBP, state police, the Army and the Railway Protection Force, was part of that broader strategic shift, prompted by heightened concern over both external and internal vulnerabilities, sources added.

Revived airbase raises concern

Though Siliguri Police Commissioner C Sudhakar declined to provide specifics to the media, saying it was only a routine meeting and that security-related discussions could not be disclosed publicly, a senior security official, who attended the review, said the discussions centred on improving intelligence-sharing and strengthening rapid-response mechanisms across agencies.

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This meeting comes soon after the deployment of three fully operational garrisons along the Indo-Bangladesh border, and a concurrent strengthening of the air-defence grid around the corridor.

India’s concerns stem from a series of developments in Bangladesh that security officials say carry significant strategic implications, primary among them is the reported revival of the WWII-era Lalmonirhat Airbase in northern Bangladesh, barely 135 km from the Siliguri Corridor, with active involvement of the Chinese government.

The possibility of the airbase, which was recently inspected by a team of Chinese officials, becoming a dual-use facility capable of hosting surveillance aircraft or drones has triggered fears in New Delhi of a future where Chinese military assets operate just minutes from India’s eastern lifeline.

Officials who attended the high-level security meeting warn that such a capability could allow Beijing to monitor troop movement, track logistics build-up, or even attempt to impose aerial pressure on the corridor during a conflict.

Cross-border security threats

The concern is compounded by Bangladesh’s shifting foreign-policy posture and its growing proximity to China, which has financed and constructed several strategic and infrastructure projects across the country, including ports, communication networks and manufacturing clusters, many of which are located close to India’s borders.

After Sheikh Hasina’s Awami League government fell in August last year, the new Bangladeshi administration invited Chinese companies to join the Teesta River Comprehensive Management and Restoration Project (TRCMRP), overlooking India’s security concerns over such extensive Chinese activity near the “chicken’s neck”.

For India, the concern is not limited to Chinese activity alone. Rising incidents of illegal crossings and suspicious movement along the Indo-Bangladesh border have added a new internal dimension to the challenge.

Also read | Pakistan-Bangladesh axis emerges as India falls out of Dhaka's favour

Multiple Bangladeshi nationals have been detained in recent weeks in North Bengal, including one apprehended near an Indian Army installation, found carrying documents that raised suspicions of his links to Bangladesh’s intelligence agencies.

In another incident, a 26-year-old Bangladeshi man was arrested near the Panitanki border point while attempting to cross into Nepal with forged identity papers.

Mounting security anxieties

Security agencies fear that such movement through the tri-junction region could be part of a wider pattern of probing activity, routed through Nepal to avoid high-surveillance stretches of the border with India.

Infiltration and covert reconnaissance from Bangladesh, including movement routed through Nepal, pose long-term risks of espionage or sabotage, sources added. These developments have further heightened security anxieties. While external pressures from Bangladesh and China dominate current security calculations, the Union Home Ministry, in a recent report on the dynamics of Maoist insurgency, warned that internal destabilisation attempts by Maoist networks continue to pose a parallel risk across eastern India, including regions that act as feeder routes to the Northeast.

Crucially, according to the home ministry’s assessment in the report, the Maoists, particularly the CPI (Maoist) and its armed wing, the People’s Liberation Guerrilla Army (PLGA), has a strategic game plan to form a “united front” with other insurgent and terrorist groups across India, some of which are supported by external actors inimical to Indian interests.

Maoist insurgents had a robust network in Adivasi pockets in the western Assam region close to the Siliguri corridor. Besides, Nepal has historically provided cross-border safe havens for Maoist cadres during the 1990s and early 2000s, allowing training, logistics, and planning in relative obscurity. Even today, the porous India-Nepal border facilitates clandestine movement and communications that Indian security agencies monitor closely.

While there is no evidence of direct Maoist activities in the region, India’s security apparatus views the insurgents’ broader strategy of forming united fronts with other groups as a potential threat, adding to the multi-dimensional risk environment surrounding the narrow corridor.

India fortifies Siliguri corridor

In light of this evolving threat, India has adopted a multi-layered defensive posture around the sensitive corridor. A key component of this has been the establishment of three new, fully operational army garrisons along the Indo-Bangladesh border at Bamuni in Assam’s Dhubri district, at Kishanganj in Bihar, and at Chopra in West Bengal.

“These facilities significantly enhance troop mobility, surveillance and rapid-response capability across the vulnerable southern arc of the corridor, reflecting a deliberate move toward permanent force presence,” an army official said.

Also read | Bangladesh on the edge: Why fragmentation looms and what it means for India

Parallel to this, India has strengthened its air defence over the region. The deployment of advanced systems, including the S-400 Triumf, the Indo-Israeli Medium-Range Surface-to-Air Missile (MRSAM) system, and the indigenous Akash missile platform, has created a layered air-defence shield intended to neutralise or deter aircraft, drones or surveillance assets possibly operating out of Bangladesh-based infrastructure or Chinese-supported facilities.

Ground readiness has also been sharply enhanced. Troops under the Trishakti Corps (33 Corps), headquartered near Siliguri, now regularly conduct live-fire drills and mobility exercises, including those involving T-90 tanks, tailored for both riverine plains and the hilly terrain typical of North Bengal, sources further revealed.

Simultaneously, intelligence and paramilitary agencies have intensified coordination. The November 22 multi-agency review in Siliguri placed strong emphasis on real-time intelligence sharing, eliminating inter-agency delays, and ensuring a faster reaction chain in the event of suspicious movement, infiltration attempts or cross-border subversive activities.