Kashmir was free to accede to either nation. Maharaja Hari Singh, the ruler of the kingdom at the time, initially chose to remain independent but eventually opted to join India, thereby handing key powers to the central government in New Delhi. In exchange, India guaranteed him military protection and vowed to hold a popular vote on the issue.
The South Asian rivals have fought two full-scale wars over the territorial issue.
Islamabad has always said that majority-Muslim Kashmir should have been a part of Pakistan. A United Nations resolution adopted after the first war called for a referendum allowing the people of Kashmir to choose which country they wanted to join, but that vote for self-determination has never been held. Pakistan wants that referendum to take place.
India says that Pakistan lends support to separatist groups fighting against government control and argues that a 1972 agreement mandates a resolution to the Kashmir dispute through bilateral talks.