As hostilities between India and Pakistan escalate, leaders in both countries are very aware of the risks of a nuclear catastrophe.

Pakistan reported on Wednesday that it had downed two Indian jet fighters and captured one of the pilots, whom it paraded before TV cameras. India claims it shot down a Pakistani jet and says only one of its planes was downed. Whatever the truth, the bottom line is that two countries with nuclear weapons have come to blows. The air battles were the latest escalation in a tit-for-tat confrontation that has been brewing since a suicide bomber killed at least 42 Indian troops in the disputed territory of Kashmir on Feb. 14. India blamed Kashmiri militants based in—and, it claims, supported by—Pakistan.

Wednesday marked the second day in a row that Indian jets had crossed the Line of Control, which divides Indian- and Pakistani-controlled Kashmir. They had not done that in a half-century. It all comes against the backdrop of the Indian election campaign. An external threat is usually good for the incumbent, in this case Prime Minister Narendra Modi, assuming he flexes the appropriate muscles.

That’s the bad news. The good news is that the leaders of the two countries—civilian and military—seem to be keeping level heads. So far.

“We should sit and settle this with talks,” Pakistani Prime Minister Imran Khan said in a nationwide address a few hours after the military announced it had downed the Indian jets and had carried out its own incursion into Indian airspace. “All wars are miscalculated, and no one knows where they lead to. … In the case of nations that have nuclear weapons, the endgame is unthinkable.”

For those wondering why the use of nuclear weapons would even be on the table, a little context is valuable. Pakistan’s population is less than 200 million; India’s is 1.3 billion. India’s military is almost four times as large as that of Pakistan. So the odds of Pakistan holding off a full-scale Indian invasion without the use of tactical nuclear weapons are slim to none.

“I ask India,” Khan continued, with “the weapons they have, and we have, can we afford a miscalculation? If this escalates, it won’t be in my control or in Modi’s.”

There was no immediate response from Modi, but in the days after the suicide bombing of the Indian troops, both he and Khan talked about focusing on how much the two countries have in common. Even Pakistan’s powerful military was taking a conciliatory tone. A Pakistan Army spokesman said its bombing of Indian-controlled territory was designed to avoid military or civilian casualties: “The in-built message was that despite our capability, we look towards peace.”

“Sole purpose of this action was to demonstrate our right, will and capability for self defence. We do not wish to escalate but are fully prepared if forced into that paradigm,” a Pakistani Ministry of Foreign Affairs spokesman confirmed in his own tweet.

The tightly controlled Pakistani media was under instructions to toe the same line. “Keep cool,” was the message one top editor told me they had received. Across the border, jingoism dominated some newsrooms. “‘Fakistan’ stages farce,” blared a banner on India’s Times Now web stream. The bombastic anchor shouted, “If this is going to be kill for kill, then here are the repercussions. We don’t lie. Pakistan lies, viewers.”

But the jingoists were not the only voices being heard. On social media, #SayNoToWar was trending in both countries. Dinakar Peri, a defense correspondent for India’s Hindu newspaper, tweeted, “Need de-escalation before things go down further.” The Herald in Goa voiced concern about Modi’s motive for launching the initial airstrike following the terrorist bombing: “We would like to believe that an election stunt it was not. Can it be kept that way?”

At the root of the confrontation lies Kashmir, a territory divided between India and Pakistan when British India was partitioned in 1947. The territory has been the flash point for three India-Pakistan wars, the most recent in 1999. In the years since, the dispute has languished, far from the agenda of the world’s big powers.

Here in Pakistan’s commercial capital of Karachi on Wednesday, flocks of the city’s ubiquitous black raptors swooped low over the traffic-clogged streets, but they were the only things moving in the polluted, gray skies. All commercial flights were grounded as the military closed Pakistani airspace. The country’s largest newspaper, Dawn, published a screengrab from a flight tracking service that showed the air cordon.

As I write this, the hotel where I am staying is testing its emergency PA system. “Hello, hello? Mic check.” Western executives who checked out at midday thinking they were leaving for Dubai or Doha sit glumly in the lobby, wondering what to do.

Right now, the confrontation is still at the level of a schoolyard tussle, with both sides demonstrating that they can’t be pushed around. The hope is neither will pick up a rock. The rocks available to them are very big indeed.

Lawrence Pintak is an award-winning journalist and scholar who was the founding dean of the Edward R. Murrow College of Communication at Washington State University. A former CBS News Middle East correspondent, Pintak has covered dozens of wars, conflicts, coups, and revolutions on three continents. His latest book is America & Islam: Soundbites, Suicide Bombs and the Road to Donald Trump.

Twitter: @lpintak