Parliament has cleared a historic land agreement with Bangladesh to settle India’s border with its eastern neighbour. The two countries share a 4,096-kilometer-long international border, the fifth-longest in the world.

Prime Minister Narendra Modi thanked Congress leader Sonia Gandhi in the Lok Sabha after lawmakers showed rare unanimity in passing the constitutional amendment on Thursday. The bill was passed by the Rajya Sabha a day earlier. Fifteen states will now also have to clear the agreement for it to be implemented - this is not likely to be a problem given the cross-party support.

India and Bangladesh have been negotiating a land swap since 1974. Nearly 160 enclaves exist on either side of the border that are encircled by the other nation’s territory – an odd situation left over from Partition in 1947.

According to NDTV, the proposed solution would enable each side to acquire the enclaves within its borders. People living in these enclaves would have the choice to move to live in their original country of nationality or to become nationals of their 'new' country after the exchange.

This would end decades of uncertainty for tens of thousands of citizens living in enclaves on the "wrong" side of the border.

Prime Minister Narendra Modi called the passage of the bill “a historic milestone,” and Bangladesh’s envoy to India, Syed Muazzem Ali, called it a “historic and landmark day.”

There are 51 Bangladeshi enclaves with about 15,000 people within states like Meghalaya, Tripura and West Bengal. With the new agreement, these will become part of India and the people here have the option to relocate to Bangladesh if they prefer. Across the border, there are about 100 enclaves that now transfer officially to be a part of Bangladesh. The government has reversed an earlier decision to exclude Assam from the agreement.

In this land swap, India will get 510 acres while Bangladesh will get 10,000 acres. "But these are notional figures as these areas are deep inside territories of the two countries. Our borders are not getting contracted," External Affairs Minister Sushma Swaraj said in Parliament.

She said the agreement would also help to check illegal immigration, since the entire border can now be fenced.

According to the Times of India, Swaraj credited the previous UPA administration for presenting the amendment bill in Parliament in December 2013.

"Manmohan Singh is the one who started the whole thing. I have merely completed the task," she said, thanking the former prime minister who was present in the Rajya Sabha.

The maritime boundary between India and Bangladesh was settled last year. Swaraj said the only remaining issue was over the sharing of river water, primarily concerning the Teesta river.

"The way in which we are now settling the land boundary issue, we will try to settle this issue also," she said.

- Karan Singh

To Learn More:

Parliament passes historic land accord bill to redraw border with Bangladesh (Times of India)

India: Border Dispute With Bangladesh Nears an End (by Hari Kumar and Nida Najar, New York Times)

After Land Swap with Bangladesh is Cleared, PM Thanks Sonia Gandhi for Support (by Sandeep Phukan and Sunil Prabhu, NDTV)

Bangladesh thanks India for LBA ratification (PTI)