In the foothills of the eastern Himalayas, where West Bengal narrows to a sliver barely 22 kilometers wide at its tightest point, India is pouring resources into one of the most consequential infrastructure and military buildups along its northern frontier. The Siliguri Corridor, known for decades by its grim nickname "Chicken's Neck," connects the Indian mainland to eight northeastern states, and New Delhi is now racing to shield it against a scenario long feared by its military planners: that the corridor could be cut off in a crisis.

The push includes underground military facilities designed to withstand aerial bombardment, an expanded fleet of French-made Rafale fighter jets stationed to bolster air defense, and plans for a 40-kilometer underground railway link that would give India a hardened, harder-to-target alternative to the exposed surface roads and rail lines currently running through the region.

A Sliver of Land, a Nation's Lifeline

The Siliguri Corridor's vulnerability is a matter of simple geography. Squeezed between Nepal to the northwest, Bhutan to the northeast, and Bangladesh to the south, the corridor is the sole terrestrial artery linking roughly 45 million people in India's northeastern states to the rest of the country. Any disruption, whether from military conflict, natural disaster, or sabotage, would sever road, rail, and communication links to the entire northeast.

That fragility has taken on new urgency as China has deepened its military and infrastructure presence near India's northern borders, and as Bangladesh's political alignment has shifted following upheaval in Dhaka. Indian strategists have grown increasingly concerned about the prospect of coordinated pressure from both directions, a concern that has accelerated the timeline for hardening the corridor's defenses.

Going Underground

Central to India's response is a shift toward subterranean infrastructure. Military planners have long worried that the corridor's narrowness makes conventional installations, airbases, supply depots, and rail lines easy targets for missile or air strikes. Underground bunkers now being developed in the region are intended to protect command centers and logistics hubs from exactly that threat, allowing operations to continue even if surface infrastructure is damaged or destroyed.

The planned 40-kilometer underground railway link represents the most ambitious element of this strategy. By burying a critical transport link beneath the surface, India aims to ensure that reinforcements and supplies can keep moving to the northeast even if the existing above-ground corridor comes under attack or blockade. The project reflects a broader doctrine shift: rather than simply defending the corridor's surface, India is building redundancy beneath it.

Air Power as Deterrent

Alongside the underground works, India has moved to strengthen its air defenses in the region, deploying Rafale fighter jets, among the most advanced aircraft in its arsenal, to positions that allow rapid response across the corridor and the broader northeastern theater. The Rafale's long-range strike capability and sophisticated radar systems are seen as a key deterrent against any attempt to isolate the northeast by force, giving India the ability to contest the skies over a region where ground reinforcement would otherwise be difficult and slow.

A Legacy of Contested Borders

The anxieties driving this buildup are rooted in a long history of contested frontiers in the region. India's 19th-century colonial administrators also treated the area north of Bengal as a strategic buffer zone, waging campaigns to bring Sikkim and Bhutan under British influence specifically to secure the approaches to Darjeeling and the plains below. Sikkim was reduced to a British protectorate in 1890 after disputes over Tibetan influence, while Bhutan ceded its duars, the low hill passes bordering Bengal and Assam, following an 1865 war, giving British India a defensible line along the Himalayan foothills.

That same geography now defines India's modern strategic calculus. The corridor sits close to the tri-junction where Indian, Chinese, and Bhutanese territory meet near the Doklam plateau, the site of a tense 2017 military standoff between Indian and Chinese troops. Beijing's continued infrastructure expansion in the area, including roads and settlements near the disputed frontier, has kept the region a persistent flashpoint.

Bangladesh's Shifting Posture

Compounding these concerns is the changing political landscape in Bangladesh, which forms the corridor's southern boundary. Shifts in Dhaka's foreign policy orientation and its evolving relationship with Beijing have unsettled Indian officials who had long relied on a cooperative Bangladesh to reduce pressure on the corridor's southern flank. A less predictable Bangladesh, combined with an assertive China to the north, has sharpened the sense in New Delhi that the Chicken's Neck can no longer be treated as a secondary concern.

Taken together, the underground bunkers, the buried rail line, and the forward deployment of Rafale squadrons mark a significant escalation in how seriously India now treats a stretch of land that, despite its narrow width, carries outsized strategic weight. For a government intent on avoiding any repeat of past vulnerabilities along its Himalayan frontier, the message is unmistakable: the Chicken's Neck will not be left exposed again.