If you are clueless about the 1971 war, here's a quick history lesson. In 1971, the Indian Army had overrun the erstwhile East Pakistan (Bangladesh) and taken 93,000 POWs (Prisoners-Of-War). In 1972, Indira Gandhi signed the Simla accord with then Pakistani Prime Minister Zulfikar Ali Bhutto and released the Pakistani POWs. So did Pakistan, but the families of Indian soldiers claim that Pakistan did not release all the Indian soldiers. Juxtapose this against the grim reality of the Pakistani government denying the very existence of these PoWs, and you have 1971.