The mob rampaged for days, burning homes, breaking into temples and clashing with police, leaving several dead.

The victims were minority Hindus living in Bangladesh, a nation grappling with increasing extremism, and the violence drew an outcry from politicians in neighbouring India.

As the region’s traditional centre of gravity, India has a history of promoting tolerance. Prime Minister Narendra Modi has also positioned himself as the champion of Hindus against a history of victimhood.

But the erosion of human rights in India has weakened its moral high ground in a region where ethnic and sectarian tensions are worsening. Sheikh Hasina — Bangladesh’s Prime Minister and a close ally, who had just sent Modi red roses on his 71st birthday — had pointed words for India, even as she promised to hunt the culprits.

“We expect that nothing happens there,” Hasina said, “which could influence any situation in Bangladesh affecting our Hindu community here”.

India is losing leverage in South Asia as its government tries to reshape the country into a Hindu state. In marginalising and maligning its minority Muslims at home, Modi’s government has weakened India’s traditional leadership role of encouraging harmony in a region of many fault lines.

The shift could also open opportunities for China, which has used the promise of investment and access to its hard-charging economy to cultivate stronger relations with its rival’s neighbours.

“The openly partisan approach to communal issues has created a very peculiar situation for us as far as that moral high ground in neighbourhood policy is concerned,” said Yashwant Sinha, who was India’s foreign minister when the BJP was last in power in the early 2000s. “We can’t say ‘you stop it, this should not happen,’ because we ourselves are guilty of it.”

Leaders of the ruling party declined to comment. In public statements, officials have pointed to Modi’s “neighbourhood first” focus in foreign policy, something he announced soon after taking office in 2014. They say the leader is deeply invested in improving regional connections “that bear prosperity to the neighbourhood”.

In Sri Lanka, a Buddhist-majority country, the government has been taking a tougher stance towards the Tamil, a largely Hindu minority whose grievances led to a three-decade civil war, and towards its small Muslim population.

President Gotabaya Rajapaksa recently appointed a hard-line Buddhist monk to lead an overhaul of the legal system, though he has been accused of stirring hatred against Muslims and jailed for intimidating the wife of a journalist who had disappeared. The panel overseeing the overhaul effort includes Muslim scholars but has no Tamil representation.

In majority-Muslim Pakistan, where the ethnic Pashtuns and Baloch have long been marginalised, increasing Islamist extremism has resulted in vigilante action against the Hindu minority, who make up just 2 per cent of the population. They have faced repeated episodes of violence, vandalism of their temples, occupation of their land and an increase in forced conversion of minority girls, according to Pakistan’s human rights commission. Prime Minister Imran Khan has spoken out against the abuses, but to little effect.

Communal violence in one country often becomes fodder for the narrow nationalism of the other. Khan has blamed Modi for “unleashing a reign of fear and violence against India’s 200 million-strong Muslim community”.

Modi’s supporters frequently splash videos of the anti-Hindu violence in Pakistan and elsewhere in the region as justification for policies seen as discriminating against Muslims.

But such violence and the abuse of minorities is nothing new in South Asia, a region of deep ethnic and religious fault lines that is home to a quarter of the world’s population.

The traumatic partition of India and Pakistan in 1947, and the later war-driven split of Bangladesh from Pakistan in 1971, left sizable ethnic and religious minorities in each country. The domestic policies of one nation inevitably affect the population of another.

Traditionally, how India — the largest and the most diverse of the nations — tried to manage its affairs set the tone for the rest.

Even when sectarian violence flared within its own borders, India was the big brother with larger-than-life leaders like Mahatma Gandhi and its legacy of ending centuries of colonial rule through non-violence.

The policies of Modi’s BJP have chipped away at that position, not unlike the erosion of the US’s global standing on human rights during the Trump administration.

The BJP has pursued a Hindu-first agenda that has often put India’s Muslims at a disadvantage. The party has also refused to rein in hard-line elements within its ranks, sometimes leading to violence.

Hasina, Bangladesh’s Prime Minister, and others have suggested that the hardening attitudes toward Muslims in India have contributed to violence against Hindus in Bangladesh.

“The situation that happened in Bangladesh is empowering the Hindutva politics, and they are trying to exploit it,” said Mohammad Tanzimuddin Khan, a professor of international relations at Dhaka University, referring to the BJP’s Hindu nationalist ideology.

“And at the same time, the Hindutva politics of India is empowering the BJP-type politics in Bangladesh.”

The violence in Bangladesh during Durga Puja claimed seven lives, the police said.

That violence has further deepened sectarian tension in India. In recent weeks, a Right-wing Hindu group has been organising large protests in Tripura, just over the border from Bangladesh, against the anti-Hindu violence there.

The police have had to deploy heavy security to protect mosques, after members of the group vandalised at least one mosque and burned shops. A group of lawyers and activists who went to Tripura to document the damage found themselves charged with violating a draconian anti-terror law.

While some BJP officials criticised the violence, Modi himself has been largely silent. In contrast to Pakistan, where tensions with India sometimes break out into open conflict, Modi has cultivated good relations with Bangladesh, and harsh words could sour diplomatic ties between New Delhi and Dhaka.

India’s neighbours can find friends elsewhere. China, flush with development projects and loans, has actively placed itself as a potentially lucrative alternative. In addition to strengthening economic ties with Pakistan, it has also used Covid-19 vaccines and other aid to improve relations with Nepal, Sri Lanka and Bangladesh.

But the BJP’s Hindu nationalist ideology has made India more inward-looking, said Aparna Pande, director of the India initiative at the Hudson Institute. Previously, its pluralistic example of governance had avoided stoking tensions, and it took at times a paternalistic view toward its neighbours.

Now, she said, Modi’s “neighbourhood first” policy appears at odds with the backlashes caused by the Hindu nationalist vision at home.

“If you are pushing a nationalist narrative, it is difficult to then ask your neighbours to not do the same,” Pande said. “You will then see every country in South Asia becoming more nationalist and, forget about anything else, that creates a strategic challenge for India.”

Today, said Sinha, the former foreign minister, Modi’s silence “creates the impression as if we have lost control of the situation or that the State is actively encouraging violence against minorities”.

Sinha, who quit the BJP and recently joined the Trinamul Congress, was foreign minister immediately after some of the deadliest communal violence in India in 2002 in Gujarat, where Modi was the chief minister.

Sinha said such violence did not affect India’s standing because the country’s Prime Minister at the time, Atal Bihari Vajpayee, made clear that the episodes were both unacceptable and isolated.

These days, Sinha said: “The interlocutor can turn back and say ‘Why don’t you practise at home what you preach to us?’”

This article originally appeared in Telegraph India