The two nation theory , championed by the Muslim League , led to the partition of India and the creation of Pakistan in 1947. But the two wings of Pakistan , called West Pakistan and East Pakistan separated by 1600 km of Indian territory , could not live in harmony despite religious homogeneity . Their ethnic , linguistic , economic and cultural diversities could not be bridged by an emotional appeal to religion . Consequently , fissures started erupting in the politics of Pakistan soon after the Independence and with each passing year these widened . The Indo - Pak War of 1965 also contributed to this growing divide . Bereft of appropriate defense infrastructure , East Pakistan felt isolated and abandoned . Finally , the malfeasance of Pakistani leadership , after the 1970 elections , proved the proverbial last straw on the camel's back .