Why now? A preliminary investigation into the deadly attack on tourists near Pahalgam has revealed that the terrorists opened fire with AK-47s, and more interestingly, American-made M4 carbines. Why is this significant? Russian-origin AKs are the weapon of choice for most militants, terrorists, and rebel groups around the world. Their simplicity, reliability, and affordability make them ideal for combatants with limited means, operating for long durations in difficult conditions without much logistics support. American weapons do not fit this bill. In general, they require better training and upkeep to be effective, and are much more expensive — cons which do not always balance out the pros of them being lighter, more versatile, and more accurate. This is what makes an M4 carbine a somewhat unlikely weapon in the hands of terrorists, especially in a part of the world where knock-off AKs are a dime a dozen. That the Pahalgam attackers carried M4s indicates they are highly sophisticated operatives, and not the run-of-the-mill disgruntled youth. That said, it is not completely unheard of for terrorists to carry M4s, especially in the very recent past. How did the terrorists obtain M4s? There are two possible explanations for how the Pahalgam attackers got hold of M4 carbines. The first is to do with the United States’s exit from Afghanistan in 2021. At the time they pulled out from Kabul, the Americans had been fighting in the country for two decades. In the process, they had developed massive stockpiles of weapons in Afghanistan — much of which they left behind, ostensibly for the Afghan forces to use against the Taliban. Of course, the Afghan resistance folded almost immediately after the American exit, leaving the Taliban with the weaponry left behind. While some of this the Taliban kept for itself, huge caches of guns and ammo were sold to the highest bidder in Afghanistan’s busy arms markets. The beneficiaries: a motley collection of rebel groups, militias, tribal warlords, and, of course, terrorists. The other explanation for how the terrorists got hold of weapons is more straightforward: they were supplied by the Pakistani state, presumably the ISI. Pakistan also has a decent stockpile of M4s, which is used by its special forces. Why is the M4 carbine a lethal weapon? Following the military adoption of the Armalite AR-15 as the M16 rifle in the 1960s, the United States spent two decades developing an effective carbine on the same platform. Carbines are essentially rifles which are lighter, and have a shorter barrel than a standard rifle. They are meant to be used by highly mobile units, or for urban warfare, and were originally developed as rifle-caliber arms for mounted units. The M4 carbine was officially adopted by the US in 1994, and has since seen use by over 60 militaries around the world. Chambered in the 5.56×45mm NATO cartridge, the M4 can fire upto 950 rounds a minute, and has a maximum effective range of around 600 metres. Weighing only 3.5 kilos (fully loaded), it is lighter than even most modern AKs with plastic magazines and stocks. And unlike older AKs, it comes with a built-in Picatinny rail, which allows for an assortment of attachments, from advanced telescopic and night vision sights, to laser guides, and even grenade launchers. Military historian Chris McNabb refers to the M4 as “one of the defining firearms of the 21st century.” (The M4 Carbine, 2021).