The news about the Ministry of Railways sanctioning a preliminary engineering-cum-technical survey for a rail link between Kokrajhar and Gelephu has revived the talk of a direct rail link between Assam and Bhutan. If constructed, it will go a long way in improving trade, commerce, and tourism between two landlocked regions, besides deepening bilateral relations between India and Bhutan. The survey will be carried out for a 57.7-km transboundary railway line connecting Kokrajhar in Assam and Gelephu in Bhutan. India and Bhutan signed a Memorandum of Understanding in 2005 for the establishment of five railway links of which three were proposed links across the Assam-Bhutan border. The feasibility studies for the extension of the Indian railway network from the States of West Bengal and Assam to the nearest border towns in Bhutan included Kokrajhar–Gelephu, Pathsala–Nanglam, Rangia– Samdrupjongkhar via Darranga in Assam, Hasimara– Phuentsholing and bifurcation to Pasakha; and Banarhat– Samtse in West Bengal. Assam shares the longest stretch of 266 km of a total 698 km India-Bhutan border but its two Land Custom Stations at Hatisar (connecting Gelephu in Bhutan) and Darranga (connecting SamdrupJongkha in Bhutan) account for only 16% of the cross-border trade between the two neighbouring countries. Trade through Hatisar-Gelephu has been estimated at Rs 450 crore and about Rs, 950 crores through Darranga-SamdrupJognkha compared to Rs 6400 crore through Jaigaon Land Custom Station in West Bengal which presents the larger picture of trade through the Assam-Bhutan border. Railway connectivity, when materializes as planned, will provide a boost to trade across the Hatisar-Gelephu trade route and boost confidence for increasing trade volume through the Darranga-SamdrupJongkha trade route and revive other trade routes along the Assam-Bhutan border to become functional. A rail link to Kokrajhar will also provide Bhutan with the railway connectivity with Bangladesh via Assam and Tripura, besides West Bengal. Completion of the Agartala-Akhaura rail link will help Bhutan explore railway connectivity via Assam and Tripura for increasing trade and commerce with India and Bangladesh. The disruption caused by massive landslides in Dima Hasao's snapping railway connectivity with Barak valley, Tripura and Mizoram point toward the challenges involved. Addressing such challenges is critical to triggering confidence among stakeholders of transborder trade and commerce through the Northeast. External Affairs Minister S Jaishankar, in his speech at the Natural Allies in Development and Interdependence (NADI) Asian Confluence River Conclave in Guwahati in May said that India was looking at the feasibility of creating a cross-border rail line between Bhutan and India, running through Assam. A pilot launch of Bhutanese products in big Indian retail outlets in Guwahati, Kolkata and New Delhi is on the anvil, he said which points towards the future growth trajectory of trade and commerce between India and Bhutan via Assam. He also emphasized that "an India that is more connected to the North East and the North East that is more connected to India's neighbours will mean a complete transformation of the regional economy. Instead of being regarded as a frontier, it will emerge as a hub in itself." This policy focus on the Northeast under the country's Act East and Neighbourhood First policies has pushed trans-border connectivity projects in the region which are also strategically important for the country and the region. India and Nepal have already launched the first rail link between the two countries and the rail link between India and Bhutan will take transport and connectivity in Bangladesh Bhutan India Nepal (BBIN) sub-region to a new dimension that will be crucial for deepening multilateral cooperation among BBIN countries. While trans-border connectivity projects are ongoing and those in the pipeline will shape a new transport regime in the sub-region Assam and other states in the Northeast getting ready to take advantage of the changing situation will require them to diversity their export baskets to cater to the requirements of the markets in the neighbourhood. The region has a lot to offer for markets in these neighbouring countries, but connectivity issues pose bottlenecks in harnessing these benefits. Caution needs to be taken to ensure that the connectivity projects are ecologically sustainable and environmental impact mitigation requirements are not ignored in the name of expediting the projects. Tributaries of the Brahmaputra originating in Bhutan causing high flood situations in downstream areas in Assam due to torrential rain call for watershed management in Bhutan hills and downstream areas so that impact of excess water release from mega hydropower dams in Bhutan can be minimized. Deforestation in the catchment of the rivers aggravates the flood situation and triggers erosion. The survey for the Kokrajhar-Gelephu rail link covering all these aspects will be vital for the sustainability of the proposed connectivity project. A geo-technical investigation carried out for the project needs to consider the climate change impact and changing rainfall patterns. Train links between Assam and Bhutan have the potential to unlock the untapped potential of both landlocked regions.