In addition to Israel, the Biden administration has sent an enormous quantity of materiel to Ukraine since Russia’s 2022 invasion. Meanwhile, the U.S. is gearing up to rush an influx of arms to Taiwan in hopes of deterring a possible Chinese attack on the island, which Beijing considers a rogue province. The U.S. Defense Department already struggled to maintain robust munitions levels in the decades before the recent wars in the Middle East and Europe. But the shipment of arms to Israel, Ukraine and Taiwan has placed intense pressure on the Pentagon’s inventory, forcing it to make challenging risk management assessments as it tries to move the defense industry from peacetime production to a wartime footing.

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The shortages are in part symptoms of a chronic issue, said a senior defense official, granted anonymity to discuss the closely held process. The Pentagon has long used munitions as a “bill payer,” neglecting their purchase in favor of platforms like ships or planes in the annual budgets, the official added. Over time, the low orders led to some companies exiting the market, which in turn reduces the number of businesses that will build those munitions and the speed at which they come off the line.

see, this is why you're supposed to have a state-owned arms industry, since when you leave things to the whims of the free market, obviously a ton of companies are going to go out of business during peacetime, like what do you expect to happen

... the U.S. could use Javelin anti-tank missiles or Tomahawk cruise missiles against at least four major competitors: China, Russia, North Korea and Iran. But the military doesn’t necessarily expect to fight all four adversaries at once and may calculate requirements based on fighting two enemies at a time.

well damn, I sure hope we don't end up facing a couple crises at once! now, that'd be a real bad situation for us

... The U.S. often serves as a “backstop” for European allies, Clark noted, pointing to NATO’s heavy reliance on American munitions in its 2011 Libya campaign. “It’s not so much, are we going to have enough weapons to sustain our own capacity for a ground war, because we probably do,” Clark said. “It’s, do we have enough to sustain our own capacity to fight and also support our European allies who may need augmentation because clearly they don’t maintain the magazines to sustain themselves.” Others interviewed about the munitions requirements process also noted it lags behind real-world events and is closely tied to the Pentagon’s war plans, which usually project short conflicts instead of the reality of longer, protracted wars.

well, good thing protracted wars never happen!

But the U.S. could still quickly run through certain munitions even in a short conflict with a major adversary like China. A wargame conducted by the Center for a New American Security think tank and the House Committee on the Chinese Communist Party last year found the U.S. would run out of long-range, precision-guided munitions in less than a week in a fight with China over Taiwan. Outgoing committee Chairman Mike Gallagher, R-Wis., subsequently told Defense News that America’s inventory of long-range anti-ship missiles stood at 250 last spring, noting a conflict with China would require at least 1,000.

Since the Israel-Hamas war began in October, the U.S. has also used weapons that could be relevant to an Indo-Pacific battle, like the Standard Missile-6 and Tomahawks, to respond to Houthi attacks on Red Sea shipping lanes off Yemen’s coast. “Is it a sustainable, long-term strategy to use million-dollar munitions to shoot down drones and loitering munitions that are $10,000, $15,000, $20,000 a piece?” Rep. Rob Wittman, R-Va., asked Gen. Michael Kurilla, the U.S. Central Command leader overseeing forces in the Middle East, during a House hearing in March.

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The Pentagon hopes the foreign aid legislation will allow it to continue large-scale arms transfers to friendly countries. And as the department replenishes systems to those three partners, it hopes the additional munitions demand will pump resources into lagging munitions production lines. A significant chunk of that will go toward increasing domestic munitions capacity in the U.S. ... But even with the foreign aid legislation, expanding industrial base capacity is no simple task. ... Defense Secretary Lloyd Austin told Congress in October that some contractors have required employees to work additional shifts to keep up munitions production rates, highlighting labor shortages in the industrial base.

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A former senior Pentagon official who now works in the defense industry, speaking on the condition of anonymity because the individual was not authorized to talk to the press, told Defense News the Pentagon is generally willing to take more risks on munitions inventory levels than in other areas, expecting that Congress will quickly fund replenishment efforts. “The mentality in the Pentagon is if I do get in a fight, Congress is going to be real responsive to give me as much money as I need,” the former senior defense official said. “Right now, we’re having a problem replenishing artillery for a war in Europe that we’re not even in.”