On 31 August four million Indians could become stateless. In Bangladesh's war of independence from Pakistan fifty years ago, millions of Bengali Muslims fled to Hindu Assam, giving it the second largest Muslim population of any Indian state after Kashmir. Last year, the Assam government published a national registry of citizens, listing everyone who is legally resident. Four million Muslim people who have lived there for decades were not on the list. Unless they can prove a pre-1971 claim to residence, they will be deemed illegal. Bangladesh will not accept the deportation of millions of people who have lived in India since the 70s. Many of these people were born inside India after 1971. Should they be ‘returned’ to a country they have never known? The Assam authorities are building detention camps which could constitute a horrific human rights violation.