More than 400 people have been killed in Kabul after Pakistan bombed a drug rehabilitation facility, the Taliban government said on Tuesday (March 17). Pakistan has denied the claim, saying it “precisely targeted military installations and terrorist support infrastructure” only.The deaths mark a new escalation in the Pakistan-Afghanistan conflict that many hadn’t expected would turn out to be so long and so bloody. From border areas, the air strikes have moved inland, including capital Kabul. Why are Pakistan and Afghanistan fighting, and where can the war go from here? Here’s all you need to know, in five points.The immediate trigger is the series of terror strikes in Pakistan by the Tehreek-e-Taliban Pakistan, also called the TTP or the Pakistan Taliban, and the Taliban government’s complete refusal to act against it despite repeated requests and threats.An offshoot of the Taliban movement now in power in Kabul, the TTP wants Pakistan to run on a strict interpretation of the Quran, and opposes the current “not Islamic enough” regime that collaborates with the US.Founded by Baitullah Mehsud in 2007, the TTP has been a headache for the Pakistani State for almost 20 years, orchestrating some of the worst terror attacks on its territory. It operates mainly in the Khyber Pakhtunkhwa region bordering Afghanistan. The Pashtun population in this area is spread on both sides of the border with strong cultural and family ties.Also on Pakistan | For Pakistan, more friends abroad, more fires at home. For New Delhi, a problem. Here’s whyWhen the Taliban came back to power in Kabul in 2021, Pakistan hoped they would help their once-benefactors crack down on the TTP. However, the TTP has become more emboldened and more deadly. Increasingly, it is also capitalising on the genuine grievances the Pashtun population has against the Pakistani State. Thousands of civilians have been killed in terror attacks and the State’s response to those attacks.Before declaring “all-out war” on February 27, Pakistan had tried different methods to get the Taliban to act against the TTP.Story continues below this adIt tried negotiations, facilitated by Turkey, Qatar, Saudi Arabia, and China. It tried economic pressure, closing off its border with Afghanistan and disrupting the land-locked country’s trade. It sent back millions of Afghans, many settled in Pakistan for decades. It tried limited strikes, with both countries trading firepower last year.With nothing working, it is now going for “all-out war”, named Operation Ghazab lil-Haq. Afghanistan has carried out retaliatory strikes.What has been the impact of the war so far?While the exact death toll is unavailable, both sides claim to have inflicted heavy damage on each other. Going by various announcements made by both parties since February 27, around 1,000 people are dead. Both claim to have killed soldiers and “terrorists”, and accuse the other side of killing civilians.Story continues below this ad Two women watch as rescue workers and officials inspect the site of a late-Monday airstrike at a drug rehabilitation hospital in Kabul, Afghanistan, Tuesday, March 17, 2026. AP/PTIThere has been displacement and economic damage in both countries with already-struggling economies.Georgette Gagnon, officer-in-charge of the UN mission in Afghanistan, recently told the UN Security Council that this conflict, along with the Iran war and the Taliban’s international isolation, were compounding the country’s economic troubles. “If these issues are not dealt with, Afghanistan could again become a driver of regional and global instability in the form of out-migration, terrorism, narcotics and more,” Gagnon said.For Pakistan, a prolonged conflict risks worsening the security situation at home. The TTP has thrived because it enjoys local support, specially among the Pashtuns, in Khyber Pakhtunkhwa. Indiscriminate air strikes and the resultant deaths and destruction can harden resentment against the State.Also, with the State busy with this conflict and the Iran war, the Baloch insurgents could spot an opportunity to rev up activities.Story continues below this adOne effect of the two wars has been the Saudi Arabia-Pakistan mutual defence pact, signed amid much fanfare last year, coming under scrutiny. Both countries are under attack, but neither has shown any inclination of rising militarily to the other’s aid yet.Ideological affinity is one big reason. The Taliban and the TTP have evolved from the same belief systems and have similar aims, rooted in the Islamic Jihad worldview.Kabul also wants to assert that Islamabad should not see the Taliban as its puppet because of the past support rendered.Then is the fact that any strong action against the TTP will be unpopular with the Pashtuns in Afghanistan.Story continues below this adAlso, if the Taliban were to crack down on TTP militants, they could join other terror networks in the region, like the Islamic State–Khorasan Province (ISKP or ISIS-K), and turn on the regime in Kabul.Where could the Pakistan-Afghanistan war go from here?This is unclear. When asked what Islamabad’s endgame in this war is, Ali Chishti, a defence and security expert from Pakistan, claimed, “Pakistan has taken over posts 30 km deep inside Afghanistan, with the idea that these posts were used to help the TTP infiltrate into Pakistan. It aims to establish a buffer zone near the border, so the TTP cannot use these areas to attack Pakistan using drones and artillery.” Chishti also said Pakistan wanted to “bring some cost to the Taliban regime as part of its punitive deterrence policy”, and “destroy the leftover NATO weapons to deplete the TTP’s capacity.”In terms of conventional military strength, Pakistan has a huge advantage over Afghanistan. But the Taliban is adept at guerrilla warfare, and can continue to inflict damage on a variety of targets inside Pakistan. Also, the Taliban government has greater capacity for enduring hardship than the government in Pakistan.Most parties that could negotiate between Pakistan and Afghanistan are caught up in the Iran war. China, which has economic stakes in both countries, including its prized Belt and Road initiative, has been trying to talk to both to cease hostilities.What should India watch out for?Story continues below this adConflict and instability in the neighbourhood is never good news for India. Also, the Pakistan government has been accusing India of supporting and egging on both the TTP and the Kabul regime.India has cautiously stepped up its engagement with the Taliban regime over the past year. In the current conflict, it has criticised Pakistan for killing civilians, specially in the month of Ramadan.