China and India have sent tens of thousands of soldiers and advanced military equipment to their disputed border, as troop deployments in the region reach the highest level in decades. Both countries have built up infrastructure at the border in recent months, including insulated cabins and huts to keep troops stationed there through the frigid Himalayan winters. The deadliest confrontation between the two countries in decades occurred there in June 2020 in the Galwan Valley, where 20 Indian and four Chinese soldiers were killed.