The anti-ISIS campaign has hit a bit of , but the allied effort against the jihadist militant group has an even more basic challenge on its hands. We’re bombing ISIS so much that we need a lot more bombs.

According to the , the pace and scale of U.S. bombing missions against ISIS has “strained U.S. supplies of... three preferred precision-guided munitions: Lockheed Martin’s Hellfire missile, and Boeing’s small diameter bomb and joint direct attack munition, or JDAM.”

Luckily this “strain” is more of a supply management annoyance than an acute shortage, at least for the time being. American military planners apparently have to shift supplies from Europe and the Pacific to the anti-ISIS fight, and then backfill those arsenals “when new munitions arrive.”

This bomb crunch might have something to do with the increasing cadence of U.S. operations in Iraq and Syria. According to , U.S. forces flew 11,825 sorties with at least one weapons release over the course of anti-ISIS operations in 2016, compared with 9,912 the year before. In terms of total weapons dropped, the number ticked upward to 30,743, from 28,696 in 2015.

During its first year, one of the chief criticisms of Operation Inherent Resolve was that the U.S.-led coalition against the jihadist group—but coalition gains in Iraq and Syria, and the recent push against ISIS in Mosul could explain the uptick in munitions use.

The ISIS operation is bigger and longer than anything U.S. military planners thought they would have to deal with in the immediate post-Iraq war period, and there’s been news of tightening smart-bomb supplies . The U.S. is already dropping of its bombs on Iraq and Syria often on the kind of stationary targets that make for ideal smart-bomb fodder. The increasing need for complex and previously under-produced weapons is of course fantastic news for the precision bombs’ builders: In early 2015, Boeing was apparently producing only 40 JDAM guidance systems a day, a number that the Journal reported should hit 150 by July.

In a way, it’s remarkable that U.S. production of sophisticated air-based weapons was that low only a year ago, given the emergence of new security threats like ISIS and the U.S. public’s non-existent appetite for large-scale ground warfare. Each of these weapons are perfectly suited for an era of the U.S. eliminating the vast majority of its enemies from the air.

As the Journal reports, the JDAM is the most frequently used of these precision systems. A tail kit that dramatically improves the performance of a typical, hulking dumb-bomb, the JDAM includes an inertial and GPS-based navigation system and can compensate for weather-related factors that are sometimes responsible for . Assuming the GPS doesn’t fail, the JDAM can reduce the of a 2,000-pound munition to a fairly miniscule 30 feet. The other two systems are also accuracy-oriented weapons: Boeing’s small diameter bomb packs 50 pounds of explosives but has guide wings and a tapered nose section designed to penetrate buildings or other hardened stationary targets. The Hellfire missile is a anti-armor weapon and practically an icon of modern warfare by now.

A military whose combat activities largely consist of aerial attacks on militant bases, bunkers, vehicle columns and the like has a heavy and, as it turns out, pretty continuous need for weapons like these—after all, the U.S. has been bombing ISIS since the summer of 2014. The military’s frequent use on these weapons is an extension of the U.S.’s reliance on air power and low-footprint special operations forces to take on new security challenges like ISIS. If your wars are now largely based on bombing the enemy from the air—rather than on holding territory, building up local proxies, or mobilizing large numbers of ground forces—you’re going to need a lot of precision bombs, particularly if you care about preventing unintended casualties.

On that note, the JDAM supply crunch probably isn’t solely a reflection of the U.S.’s shift to aerial warfare. The tailkit’s heavy use likely has something to do with the U.S. military’s sensitivity to reducing civilian deaths as well.

The Pentagon has a spotty recent record as far as the morally and legally vexing matter of civilian deaths goes: it took until mid-2015 for the U.S. to non-combatant deaths in its anti-ISIS campaign, while a single coalition airstrike in Syria 18 civilians last July. Outside of the ISIS fight, U.S. forces a Doctors Without Borders hospital in Afghanistan in October of 2015, believing that the Taliban were using the facility as a base.

No aerial munition is precise enough to eliminate all danger to civilian life however responsibly it’s used, and the fault for battlefield mishaps often lies in the murkier regions of subjective human judgement. But a system like the JDAM, which improves the accuracy of existing weapons, at least reduces the chances of a successful and carefully executed U.S. strike killing non-combatants. Its widespread use over the course of the anti-ISIS campaign—to the point of its apparent near-shortage—is a sign that the US military really does care about limiting the humanitarian consequences of its operations.

Then again, the alleged 300 civilian deaths as a of coalition anti-ISIS strikes are a reminder that ending civilian casualties is much more than just a technological problem.

is a New York-based writer and editor who has reported from throughout Africa and the Middle East.