After all, both countries have long been nuclear powers -- a deterrent that encompasses the lives of a combined 1.4 billion people. Both nations have also seen some years of relative peace along their border, a break from the wars that pockmarked the 20th Century.
And yet, hours after 18 were killed in an attack on an army base in Indian-administered Kashmir, the director-general of military operations for the Indian Army announced that the terrorists carried gear which had "Pakistani markings."
The allegation unleashed a torrent of fury on social media.
"Pakistan is a terrorist state and it should be identified and isolated as such," tweeted Rajnath Singh, India's home minister.
Ruling Bharatiya Janata Party's Secretary General Ram Madhav took to Facebook. "For one tooth, the complete jaw," he posted, seeming to imply a disproportionate retaliation.
On India's many TV news channels, a steady drum beat calling for war gained momentum, reaching a crescendo of sorts in primetime.
Arnab Goswami, the host of the country's most-watched English news hour, expressed rage at Pakistan: "We need to cripple them, we need to bring them down on their knees."
One of his guests, a retired army general, went a step further: "We must be seen as inflicting punishment on Pakistan by non-terrorist means ... the nation needs a catharsis!"
But what about the ready nuclear arsenals both countries possessed? Surely that would be a deterrent?
The retired army man, Major General G. D. Bakshi, had a clear answer: "Pakistan is one-fifth the size of India. If we fire even a part of our arsenal, most of it will be on the Pakistani Punjab, from where the Pakistani army comes: Not a crop will grow there for 800 years!"
"Let's stop self-deterring ourselves," he cried.
Pakistan put together a terse response.
Sartaj Aziz, the foreign affairs adviser to Pakistan's Prime Minister, issued a statement saying the country "categorically rejects the baseless and irresponsible accusations being leveled by senior officials in Prime Minister Modi's government."
Pakistan's Ministry of Foreign Affairs spokesman told CNN that India was "desperately looking for ways to deflect the world's attention from the situation in Indian-administered Kashmir," referring to the protests and unrest there.
And emotions have boiled over on the Pakistani side, too.
In New York on Monday, an Indian journalist was reportedly asked to leave a press briefing by the Pakistani foreign secretary.
"Remove this Indian," were the words an official used in Hindi, according to NDTV, the Indian news channel whose reporter was purportedly forced to walk away.
"It's easy to get carried away by the public rhetoric we're seeing," says Ajai Shukla, a former Indian army colonel who is now the strategic affairs editor of Business Standard.
Sunday's attack is not the first deadly attack on Indian soil that New Delhi has accused Pakistan of having a hand in.
In January, another Indian military base was attacked in northwestern Punjab, not far from the border with Pakistan. And then there were the Mumbai attacks in 2008 in which 164 people were killed.
While Indian officials continue to link those attacks to the Pakistan government, Islamabad has consistently denied any involvement.
In each of these terror attacks, and others like them, there have been calls for a strong Indian response.
"When it makes decisions, the (Indian) government is guided by realities, not by a public outcry," says Shukla. "They realize that if they do attack Pakistan it does not play out in India's favor."
Shukla points out that India is not strategically prepared to launch an attack -- which he says is a "failure of the planning process."
One also cannot ignore the fact that Pakistan has the 11th biggest army in the world, says Shukla.
"We're in a symmetrical relationship," he says. "The consequences of any form of attack are far worse than people realize."
Perhaps one difference with Sunday's attack, as compared with previous ones, is that some of the calls for an Indian retaliation are coming from within the government itself, which may necessitate action if only to save face.
Indian activists burn an effigy of Pakistan's Prime Minister Nawaz Sharif during a protest against Pakistan, in New Delhi September 19, 2016.
Pakistan is watching the rhetoric in India very closely, says Musharraf Zaidi, an Islamabad-based commentator who has previously served as the principal adviser to the country's foreign minister.
"The sentiment of hurt and anger in India is understandable," says Zaidi. "But the Indian assertion that the attackers were from Jaish-e-Mohammad, within a mere three to four hours of the attack, and the notion that the group is an extension of Pakistani policy, is completely counterintuitive to even the worst, most cynical notions of Pakistan."
Zaidi says that while Islamabad may once have been supportive of groups that operated in Kashmir in the 1990s, Pakistan had long eschewed that path, with consistent and public statements from the Prime Minister and the army chief.
"In 2016, that would be a suicidal policy. Pakistan is a country that is trying to stitch together an economy. It is trying to market itself as a hub of trade for countries like China," Zaidi said.
India's tough rhetoric and calls for isolating Pakistan are a bonanza for hawks on both sides, says Zaidi: "It undermines the voices of reason."
The next steps of diplomacy -- or a war of words -- are likely to play out in New York this week on the sidelines of the UN General Assembly. New Delhi is expected to call for sanctions on its neighbor, for what it alleges are clear moves to support terrorism.
Islamabad, meanwhile, is expected to highlight unrest in Indian-administered Kashmir, where a two-month-old curfew persists after mass demonstrations and violence.
India's approach will be crucial.
For decades, New Delhi has been resolutely aloof on foreign policy: It was one of the founders of the "Non-Aligned Movement," which kept the country neutral to superpower influence.
But at last week's NAM meeting in Caracas, India was not represented by its Prime Minister for the first time since 1961.
Instead, Indian Prime Minister Narendra Modi has made a point of cozying up to the United States. He has met with US President Barack Obama eight times since 2014, and three times so far in 2016.
Modi's foreign policy is decidedly more aligned and decisive -- perhaps one reason why his supporters expect a muscular move against Pakistan. (On Monday, for example, #MakePakPay was trending on Twitter in India.)
But the overwhelming prerogative for both India and Pakistan remains growth, not war.
And in the past few years, India has not heeded public calls for attacking Pakistan and that strategy has served it well.
According to a survey released Monday by the Pew Research Center, 81% of Indians hold a favorable view of Modi and 61% approve of his handling of terrorism. While 73% of Indians hold an unfavorable view of Pakistan, 56% favor talks between the two countries to reduce tensions, according to the survey.
Much of the world will be hoping Modi listens to the polling numbers, and not the fevered rhetoric on social media.