The recent spike in tensions between India and Pakistan, explained

India launched airstrikes on Pakistani territory on Tuesday. Pakistan has vowed to respond.

Tensions between two nuclear-armed countries, India and Pakistan, are at one of the highest points in decades — and could escalate further.

On Tuesday morning, India launched an airstrike on Pakistani territory, reportedly targeting a militant training facility. The airstrike was in retaliation for a suicide bomb attack that killed dozens of Indian troops in the Indian-controlled part of Kashmir, a disputed border region, earlier this month.

India blamed Pakistan for the suicide attack, and Indian Prime Minister Narendra Modi vowed to “avenge every tear that was shed” for the victims. That vengeance came on Tuesday in the form of an airstrike — the first time India has sent warplanes into Pakistani territory since the 1970s.

Pakistani Prime Minister Imran Khan has now promised to respond. Khan also called a special session of the National Command Authority, the Pakistani government arm that oversees the country’s nuclear weapons, according to the New York Times.

After the initial attack on Tuesday, a Reuters correspondent cited a statement from an Indian defense ministry spokesperson saying that the two sides were exchanging gunfire.

The situation is incredibly tense, and many fear that things could escalate out of control, potentially even ending in the unthinkable: the use of nuclear weapons.

Although Tuesday’s events represent India’s most significant airstrike against Pakistan in 50 years — and the most serious escalation in decades — experts caution that the two countries are still very far away from that frightening scenario.

In order for either country to resort to using their nuclear arsenals, things would have to ramp way up, Vipin Narang, a nuclear expert and associate professor of political science at MIT told me — for example, an Indian ground invasion across the border.

At this point, he said, “we’re nowhere near that.”

India and Pakistan have been engaged in simmering conflict for decades

India and Pakistan are neighbors who have been engaged in varying levels of conflict for decades. As Tom Hundley wrote for Vox last year:

India and Pakistan have gone to war four times since 1947, when Britain partitioned what had been a single colony into Hindu-majority India and Muslim-majority Pakistan. They have been in a state of constant hostility ever since, and for the past two decades, they have been locked in a frightening nuclear arms race on land.

The main source of conflict at the moment is Kashmir, a disputed border region between the two countries.

On February 14, a massive suicide attack killed dozens of Indian soldiers who were traveling in a convoy to the city of Srinagar, in a part of Kashmir that’s under India’s control.

Jaish-e-Mohammed (JeM), an Islamist militant group that wants the disputed border region to become part of Pakistan, claimed responsibility for the attack. The group is designated as a terrorist organization by the US State Department, as well as the United Nations, the United Kingdom, and India.

Since its founding in 2000, JeM has carried out numerous high-profile terror attacks inside India, and is believed to responsible for the kidnapping and beheading of American journalist Daniel Pearl in 2002.

That same year, Pakistan officially banned JeM. Yet today, some 17 years later, the group continues to exist inside the country, and is still capable of carrying out deadly attacks outside of it.

That’s the reason why India blamed Pakistan’s government for the February 14 terror attack. India says Pakistan’s government allows JeM to operate in the country freely and is demanding that the government take action to prevent further attacks from being carried out.

India also retaliated by launching an airstrike against what it says was a major JeM training camp. In doing so, India’s planes appear to have crossed the Line of Control, or LoC, an extremely sensitive dividing line between India and Pakistan in Kashmir, which the country had been careful to avoid in the past.

So it was a major provocation, and one that dramatically ratcheted up tensions between the two nuclear powers. But that doesn’t mean a full-on war — let alone a nuclear conflict — is inevitable, or even likely.

The strike doesn’t mean war is inevitable. Far from it.

In a statement to Vox, Michael Kugelman, a South Asia expert with the Wilson Center, said that it was more likely that the conflict would play out in words than in actions. “Look for each side to vent and blow off steam for a while so that angry constituencies are appeased. And then we can assume the smoke will clear,” he said.

Pakistan’s response so far suggests that it may be trying to deescalate things. Senior officials have downplayed both how much damage the strike caused and how far into Pakistani territory the Indian planes actually flew. Pakistan’s top military spokesperson claimed the Indian strike hit an open area, and that there were no casualties. (India, on the other hand, claims the attack killed a “very large number” of militants.)

However, Pakistan’s prime minister has promised to act. Which means there’s certainly a chance things could continue to escalate — a possibility Kugelman acknowledged.

“If India decides to stage another strike in quick succession, then all bets would be off and some type of Pakistani retaliation could follow,” Kugelman said. “Also, if there’s another terrorist attack in Kashmir claimed by a Pakistan-based group, that could lead to escalation in a hurry.”

Alex Ward and Jennifer Williams contributed reporting to this article.