Bangladesh

India and Bangladesh share a long relationship built on a common history, culture and language.

History, because Bangladesh (earlier called East Pakistan) was born in 1971, as a result of a war between India and Pakistan. Language, because Bangla is spoken both in Bangladesh and in India's state of West Bengal. A language does not stop at a border.

Their land border is even longer than India's border with China. It runs along West Bengal, Assam, Meghalaya, Tripura and Mizoram.

They also share many rivers that come from the Ganga and the Brahmaputra. These rivers matter for farming, fishing, transport and the jobs of millions of people in both countries. A river cannot be divided like land: what happens upstream reaches the people downstream.

The two countries work closely together in diplomacy, trade, security and culture, making this one of the most important relationships in South Asia.

They share a coastline too, and the Sundarbans National Park, a UNESCO World Heritage Site, which the two neighbours protect and manage together.

The Sundarbans is the largest mangrove forest in the world. About two-thirds of it lies in Bangladesh and the rest in India. It is home to the Bengal tiger and many other species, and it protects the coast by acting as a barrier against cyclones.

Because of global warming and climate change, experts expect Bangladesh to face rising sea levels and stronger cyclones, and many people may lose their homes or livelihoods. The Sundarbans stand between the sea and the people on both sides — so protecting them protects both nations at once.