I see: Sino-Indian War
In 1962, the world's two most populous countries went to war. The Sino-Indian War claimed about 2,000 lives and played out in the harsh terrain of the Karakoram Mountains, some 4,270 meters (14,000 feet) above sea level.
BACKGROUND TO THE WAR
The primary cause of the 1962 war between India and China was the disputed border between the two countries, in the high mountains of Aksai Chin. India asserted that the region, which is slightly larger than Portugal, belonged to the Indian-controlled portion of Kashmir.
China countered that it was part of Xinjiang.
The roots of the disagreement go back to the mid 19th century when the British Raj in India and the Qing Chinese agreed to let the traditional border, wherever that might be, stand as the boundary between their realms. As of 1846, only those sections near the Karakoram Pass and Pangong Lake were clearly delineated; the rest of the border was not formally demarcated.
In 1865, the British Survey of India placed the boundary at the Johnson Line, which included about 1/3 of Aksai Chin within Kashmir. Britain did not consult with the Chinese about this demarcation because Beijing was no longer in control of Xinjiang at the time. However, the Chinese recaptured Xinjiang in 1878. They gradually pressed forward, and set up boundary markers at Karakoram Pass in 1892, marking off Aksai Chin as part of Xinjiang.
The British once again proposed a new border in 1899, known as the Macartney-Macdonald Line, which divided the territory along the Karakoram Mountains and gave India a larger piece of the pie.
British India would control all of the Indus River watershed while China took the Tarim River watershed. When Britain sent the proposal and map to Beijing, the Chinese did not respond. Both sides accepted this line as settled, for the time being.
Britain and China both used the different lines interchangeably, and neither country was particularly concerned since the area was mostly uninhabited and served only as a seasonal trading route.
China had more pressing concerns with the fall of the Last Emperor and the end of the Qing Dynasty in 1911, which set off the Chinese Civil War. Britain would soon have World War I to contend with, as well. By 1947, when India gained its independence and maps of the subcontinent were redrawn in the Partition, the issue of Aksai Chin remained unresolved. Meanwhile, China's civil war would continue for two more years, until Mao Zedong and the Communists prevailed in 1949.
The creation of Pakistan in 1947, the Chinese invasion and annexation of Tibet in 1950, and China's construction of a road to connect Xinjiang and Tibet through land claimed by India all complicated the issue. Relations reached a nadir in 1959, when Tibet's spiritual and political leader, the Dalai Lama, fled into exile in the face of another Chinese invasion. Indian Prime Minister Jawaharlal Nehru reluctantly granted the Dalai Lama sanctuary in India, angering Mao immensely.
SINO-INDIAN WAR
From 1959 forward, border skirmishes broke out along the disputed line. In 1961, Nehru instituted the Forward Policy, in which India tried to establish border outposts and patrols north of Chinese positions, in order to cut them off from their supply line.
The Chinese responded in kind, each side seeking to flank the other without direct confrontation.
The summer and fall of 1962 saw increasing numbers of border incidents in Aksai Chin. One June skirmish killed more than twenty Chinese troops. In July, India authorized its troops to fire not only in self-defense but to drive the Chinese back. By October, even as Zhou Enlai was personally assuring Nehru in New Delhi that China did not want war, the People's Liberation Army of China (PLA) was massing along the border. The first heavy fighting took place on October 10, 1962, in a skirmish that killed 25 Indian troops and 33 Chinese soldiers.
On October 20, the PLA launched a two-pronged attack, seeking to drive the Indians out of Aksai Chin. Within two days, China had seized the entire territory.
The main force of the Chinese PLA was 10 miles (16 kilometers) south of the line of control by October 24. During a three-week ceasefire, Zhou Enlai ordered the Chinese to hold their position, as he sent a peace proposal to Nehru.
The Chinese proposal was that both sides disengage and withdraw twenty kilometers from their current positions. Nehru responded that the Chinese troops needed to withdraw to their original position instead, and he called for a wider buffer zone. On November 14, 1962, the war resumed with an Indian attack against the Chinese position at Walong.
After hundreds more deaths, and an American threat to intervene on behalf of the Indians, the two sides declared a formal ceasefire on November 19. The Chinese announced that they would "withdraw from their present positions to the north of the illegal McMahon Line." However, the isolated troops in the mountains did not hear about the ceasefire for several days and engaged in additional firefights.
The war lasted just one month but killed 1,383 Indian troops and 722 Chinese troops. An additional 1,047 Indians and 1,697 Chinese were wounded, and nearly 4,000 Indian soldiers were captured. Many of the casualties were caused by the harsh conditions at 14,000 feet, rather than by enemy fire. Hundreds of the wounded on both sides died of exposure before their comrades could get medical attention for them.
In the end, China retained actual control of the Aksai Chin region. Prime Minister Nehru was roundly criticized at home for his pacifism in the face of Chinese aggression, and for the lack of preparation prior to the Chinese attack.