Talk of war on one of the world's most dangerous borders is reaching fever-pitch after a terrorist attack in Indian-administered Kashmir killed 26 tourists, infuriating the Indian government. India blames Pakistan for the massacre of civilians in the picturesque locale of Pahalgam on April 22. Pakistan's government, as with previous attacks, denies any involvement. Muslim-majority Kashmir is claimed by both India and Pakistan, with both countries controlling parts of the region separated by the line of control, the de facto border. It has been a flashpoint between the nuclear-armed adversaries for decades, with frequent terror attacks on the Indian-administered side that it blames on Pakistan. After the recent attack, Indian Prime Minister Narendra Modi vowed to hunt the "terrorists and their backers … to the ends of the earth". Experts on both sides are closely monitoring developments — but how likely is military action? 'It's time to strike' The ABC spoke to experts on both sides and most said a military reaction was very likely. Raj Shukla, a retired Indian Army general officer, told the ABC that the Pahalgam attacks were especially heinous for two reasons. "It was targeted at a certain community [Hindus], threatening our secular fabric, " he said. Media reports citing survivors of the attack said the militants identified tourists by religion, shooting only Hindus. India has not yet provided evidence about how Pakistan was involved in the attack. Ambar Shamsi, a prominent Pakistani journalist and commentator, told the ABC that India's allegations were "obviously based on a pattern that Pakistan has demonstrated, which our former prime ministers have spoken about". "The problem is the allegation this time is based on a pattern, not on solid evidence," she said. Yet Ian Hall, a professor of international relations at Griffith University, cast doubt on the credibility of Pakistani denials. "We've got pretty good evidence that elements of the Pakistan establishment and military are close with these groups," he said. "Pakistan's arguments are thin on this, but India does tend to point the finger quite early." Mr Modi has said the Indian armed forces have "complete operational freedom to decide on the mode, targets and timing" of India's response. "It is a crisis. It could be bloody, and it could be a long haul," Lieutenant General Shukla told the ABC. Retired Indian colonel and defence commentator Ajai Shukla said both countries were in a difficult position. "Unless there is something to defuse these tensions, something that provides a face-saving way out, there's very little anyone can do," he told the ABC. Will this escalate to nuclear war? Professor Hall agreed that military retaliation against Pakistan was likely — and the nature of that response would be unprecedented. "I would anticipate that we would again see something new this time," he said. "It's entirely possible they try to strike at targets in Pakistan using sea-based missiles, because Pakistan's air defences are on high alert and watching very carefully across the line of control [in Kashmir]. "Whatever we see will essentially be a surprise." While experts say a conventional military confrontation is likely, a nuclear conflagration is not. India has a no-first-use policy on nuclear weapons, whereas Pakistan has said it will use them if it faces an "existential threat". The two countries possess comparable nuclear arsenals, with India holding 172 nuclear warheads and Pakistan 170. Lieutenant General Shukla said members of the Pakistani establishment were intelligent and would not "go up the nuclear ladder", despite leaving that option open. Colonel Shukla took a similar view — that cooler heads would prevail. "That the international community would allow that, is highly unlikely," he told the ABC from New Delhi. "China would definitely intervene on Pakistan's side, and the US and Russia would try to play honest broker, and matters would grind to a halt without a conclusive ending," he said. Washington-based South Asia analyst Michael Kugelman told the ABC an all-out war was unlikely, but it couldn't be ruled out. He said the fact both countries have nuclear weapons acted as a deterrent to a full-blown conflict. "The escalation risks are limited," he said. Indian government in a 'difficult position' Still, analysts said Mr Modi was under increasing pressure to strike back hard. "His domestic support base is baying for war and to inflict massive damage, so it'll be tricky to calibrate a response," said Subir Sinha, a researcher at the University of London's School of Oriental and African Studies Shamsi, the Pakistani commentator, said while Mr Modi was under domestic pressure to "go big", that 2019 air strikes on Balakot in Pakistan could provide indication of how India would respond. "The action India took last time seemed mostly symbolic, there was not much damage, so maybe they will do something like that again," she said. Indian officials claimed to have killed a large number of terrorists, trainers and commanders affiliated with a Pakistan-based terrorist organisation Jaish-e-Mohammad. Pakistan claimed there were no casualties at all. However, Professor Hall said the Pahalgam attack "struck at the heart" of what Mr Modi's government was seeking to achieve in Kashmir: normalcy. "Modi has positioned himself as a strongman, that he'll solve these problems, but the attacks keep happening," he said. "So this puts more pressure on the Modi government to do something very decisive."