On October 20, 1962, Chinese and Indian forces fought a large engagement along their border in the Himalayas, and the fighting spread over the following weeks along two sectors, in the north east and in the western region of Ladakh. The dispute turned on the line that had been drawn by the British in 1914 and on the question of where the frontier had been settled. Each side blamed the other. Both had put troops forward over the preceding months.
The fighting lasted about a month, and the ceasefire came quickly once it was announced. Indian forces in the north east were pushed back, and there was heavy fighting at high altitude in difficult country, where cold and supply problems caused losses as well as the battles themselves. Chinese forces advanced in Ladakh as well. The government in Beijing announced a unilateral ceasefire on November 21, 1962, and then withdrew its troops to positions behind the line they had held before the fighting, which surprised observers at the time.
The war left a lasting mark on both countries. The war was short. In India it was seen as a defeat, and the government of Jawaharlal Nehru came under heavy criticism, and the army was expanded and reorganised afterwards. In China the action was presented as a defensive response to incursions. Diplomatic relations between the two countries were downgraded for years, and talks on the border have continued without a settlement. The issue stayed open.
The frontier remains unsettled in places, and patrols have clashed there in later decades, which has kept the dispute alive. Within China the episode is remembered as a defensive action to protect the border. Historians continue to argue about the aims on each side and about why the ceasefire came when it did. The two countries later built up trade and other links while leaving the boundary question open.