7. India and Bangladesh Bangladesh, formerly East Pakistan, gained its independence from West Pakistan in a 1971 civil war with the support of India, a conflict that left more than a million people dead and shattered Bangladesh's economy and infrastructure.
The new nation has struggled to recover ever since.
India and Bangladesh share the world's fifth-longest border, and an estimated 10 million to 20 million illegal Bangladeshi immigrants live in India. Bangladesh, as a Muslim-majority country and the poorer neighbour to a rising India, is often lenient towards illegal migration of its nationals to India.