India-Pakistani conflicts have deep rooted causes that go as far back as colonialism. British India was a largely Hindu nation, but also had a large minority Muslim population. Following the decolonization of the colony, different leaders held different ideals on how the nation should be controlled. Many Hindu leaders called for an Indian state for Hindus only. As a result, the former British colony fragmented into several nations. While India was formed, so were the Islamic nations of Pakistan and Bangladesh. Hostile neighbors always result in border wars and this is just another example of this. As people with different cultural and religious ideologies clash, it is impossible to tell how gruesome the outcome. In fact, I recently read that in 1947 after decolonization, as many as 1 million were killed in clashes between Hindus and Muslims.
Via Seth Dixon