Four south Asian countries are to boycott what was set to be a historic regional summit in Islamadad in November, dealing a humiliating blow to Pakistan and isolating it diplomatically.
India, Bangladesh, Afghanistan and Bhutan all said they would pull out of the South Asian Association for Regional Cooperation (SAARC) meeting following a collapse in relations between Pakistan and India, the subcontinent’s nuclear-armed rivals.
Statements by the region’s foreign ministries echoed India’s criticism on Tuesday night, which blamed “increasing cross-border terrorist attacks and growing interference of the internal affairs of member states” for Delhi’s decision to boycott the conference.
Until recently, the prospect of the Indian prime minister Narendra Modi’s visit to Islamabad had been seen as a potentially highly symbolic step towards reconciliation between Pakistan and India.
The two countries, however, have been engaged interse exchanges following an attack on an Indian army base on 18 September that killed 19 soldiers, which Delhi has blamed on jihadis based in Pakistan. The raid took place in town of Uri near the line of control that divides the contested Himalayan territory of Kashmir.
Four days later, India denounced Pakistan at the UN as the host of the “Ivy League of terrorism”.
Islamabad says India has provided no evidence linking the attack either to militants based in Pakistan or to the country’s intelligence agencies, which have long been accused of complicity with anti-India jihadi groups.
Pakistan’s defence minister has even suggested that India itself carried out the attack to deflect attention from its ongoing struggle to quell popular disturbances in the Indian part of Kashmir.
Tensions have been fuelled by television networks and social media on both sides of the border, with some pundits appearing to relish the prospect of all-out nuclear war.
Some Indian hawks have demanded retaliatory attacks against suspected militant camps in Pakistan, but Modi has sought to punish Islamabad with steps that fall short of military means.
His strategy is, however, far tougher than the relative restraint shown by previous Indian governments during earlier crises, such as that prompted by the four-day assault on Mumbai by Pakistani militant group Lashkar-e-Taiba in 2008.
In recent weeks, Modi has publicly backed separatist rebels in the restive Pakistani province of Balochistan, a move that has infuriated Islamabad. He has also questioned a key cross-border river treaty and vowed to orchestrate Pakistan’s diplomatic isolation.
That promise became reality on Wednesday when it became clear four out of SAARC’s eight members would not attend the summit, which it is Pakistan’s turn to host.
Afghanistan’s foreign ministry, which has long accused Pakistan of supporting the Taliban-led insurgency, was most stinging in its criticism, denouncing “the increased level of violence and fighting as a result of imposed terrorism on Afghanistan”.
Nine months ago, hopes were high for a rapprochement between India and Pakistan following Modi’s surprise visit to Lahore on Christmas day, the first time an Indian leader had set foot in Pakistan since 2004.
His Pakistani counterpart, Nawaz Sharif, won a landslide election victory in 2013, determined to end the decades’ long standoff and open up trade.
The two countries have fought three wars over Kashmir since independence and partition in 1947. Both sides occupy half of the Muslim-majority former princedom and claim it in its entirety for themselves.
Historic links across the former British colony have been largely severed. There are just three flights a week connecting Pakistani and Indian cities, and trade between two countries is worth only $3bn (£2.3bn), a negligible figure in relative terms, given their combined population of 1.5 billion.
Many analysts believe Modi’s December visit to Lahore angered Pakistan’s military establishment, which does not share Sharif’s enthusiasm for the rapid normalisation of relations with India.
Delhi initially showed restraint after militants attacked its Pathankot airbase near the border with Pakistan on 2 January. It blamed the Pakistan-based group Jaish-e-Mohammad, but allowed Pakistani officials to visit the airbase to help with the investigation.
Indian patience has since run out, however, not least because of Islamabad’s lack of action against either Jaish-e-Mohammad or Lashkar-e-Taiba.
Pakistan’s criticism of India for its security forces’ killing of Burhan Wani, a Kashmiri separatist commander whose death on 8 July has sparked months of civilian protests, has further poisoned relations.
Husain Haqqani, a former Pakistani ambassador to the US and critic of his country’s policies in the region, said it was not surprising that “India was looking to other forms of coercion because they feel frustrated by our behaviour”.
“But Pakistan has a tremendous capacity to withstand coercion and a mindset that wants eternal confrontation with India that is too deeply entrenched,” he said.
On Monday, Modi ordered water officials to step up efforts to divert a greater share of the three rivers the countries share under the Indus treaty, a 1960 agreement that has survived their subsequent conflicts.
“Blood and water cannot flow together,” Modi said, a rare invocation of India’s power to meddle with the Indus river system, which flows downstream into Pakistan and provides water to 65% of the country’s landmass.
Himanshu Thakkar, the coordinator of the South Asia Network on Dams, Rivers and People, said it would take up to a decade to build dams capable of reducing the flow to Pakistan.
“But it sends a signal, and that signal will have an impact,” he said. “If India builds projects to store water from its entitlement, it will provide a means for India to control water flow to Pakistan, even temporarily.”
On Tuesday, Pakistan complained to the World Bank, which brokered the original treaty, urging it to prevent India from starting construction work on the Neelum and Chenab rivers.