India and China, the world's two most populous nations, are intense rivals competing for strategic influence across South Asia. Ties have thawed since a 2020 border clash, but their 3,500-kilometer (2,200-mile) frontier has been a perennial source of tension.
The tunnel forms part of a broader infrastructure push, creating a link with roads and railways that will allow trade, troops and supplies to move year-round from India's sweltering lowland plains to the soaring icy border zones.
"This is not just a tunnel but a lifeline," said India's minister of roads, Nitin Gadkari, during a breakthrough ceremony on Tuesday at the high-altitude tunnel, which is part of a route designed to rapidly improve connectivity between Srinagar, the main city in Indian-administered Kashmir, and Leh, Ladakh's key city.
At present, road travel between the cities is blocked during winter due to heavy snowfall, which can often rise higher than a truck.
Diggers cut through the final stretch of rock in a milestone in the creation of the 13.14-kilometer (8.17-mile) Zojila tunnel, which will connect two sides otherwise cut off by snow during the bitter winters.
