Depends on how they unify the various groups. The North Koreans had thousands of years as part of Korean states or statelets, further unified by Japanese occupation and past Chinese invasions and brutality to prevent Japanese occupation. For Pakistan the borders may be too porous, and there is the issue of the Pashtuns, Baluchi, Kashmiri, and Punjabi having large portions of their brethen in India, Iran, and Afghanistan. Perhaps there is a more complete and concerted effort to expel Muslims from India, and then the efforts of West Pakistan to make Urdu the official language becomes more complete and they try setting down a Year Zero on culture? East Pakistan, as in Bangladesh, may be another interesting option. Depends a lot on a early POD relating to Bengal, Assam, Bihar, Orrisa, etc though.