India is a third the size of the U.S. mainland.
Please take a few moments to study this map and get a feel for what’s where.
The British Raj
Independence and Pakistan
Britain, supplanted as a power by the U.S. and USSR, was too weak to hold onto India .
This was the biggest factor in 1947 independence. Mahatma Gandhi was incidental.
As the Cold War loomed, Gandhi’s disciple Jawaharlal Nehru (India’s first prime minister) made it clear that India would stay neutral. Wanting an ally bordering Afghanistan and Iran, targets of Stalin’s expansionist Soviet Union, is why the British insisted on creating Pakistan. Religious tensions were a convenient, somewhat absurd excuse .
 While the U.S. ended World War 2 in 1945 by detonating atomic bombs over Hiroshima and Nagasaki, the USSR wasn’t a nuclear power until August 1949. These crucial four years are why India was hobbled by Pakistan and the institution of a foreign political system (Western capitalist democracy). China is lucky to have won independence after the Soviets got the bomb.
 When Pakistan was first proposed in 1933, India’s Muslims rejected the idea. Further, only the parts of India under direct British control (as opposed to the nominally autonomous “princely states”) became part of Pakistan. Pakistan’s existence has nothing to do with religion and everything to do with Western interests in the Cold War.
The British also split Bengal into West Bengal and East Pakistan. After Pakistan murdered three million East Pakistanis in 1971, East Pakistan became independent nation Bangladesh.
China and Nuclear Weapons
In the ensuing 1962 Sino-Indian War, Mao invaded and annexed Aksai Chin, part of Kashmir, attacking concurrently with the Cuban Missile Crisis so the USSR couldn’t intervene. This led India to develop nuclear weapons and the CPC to give Pakistan nuclear technology, which Pakistan may have passed to North Korea.
Note that during the tensions that led to the Sino-Indian War (1959 – 1961), Mao’s CPC murdered 45 million Chinese  .
 British imperialism in China caused 30 million deaths in the 1850-1864 Taiping Rebellion, starved 20 million from 1876-1879, ended the Qing Empire, and weakened China enough for Imperial Japan to murder 35 million Chinese in World War 2, setting the stage for the civil war that led to Mao’s CPC seizing power in 1949. So all this still goes back to the British.
 Mao’s CPC and the CPC post-Mao are very different entities, to the point that the CPC denounced Mao’s Cultural Revolution as the worst set-back in PRC history. As well, the modern CPC has around 80 million party members, promising some stability.
Thank you for reading!