Is the U.S. government equipped with enough ammunition to sustain all of its wars and any future ones? Pose the question to two different Pentagon officials and you’ll receive two distinct answers.

In May 2026, acting Navy Secretary Hung Cao told Congress that Washington was taking a pause on sales to Taiwan “to ensure we have the munitions we need” for the Iran campaign. A few days afterward, Defense Secretary Pete Hegseth pulled back. “Hung Cao is excellent, but I would not tie the two issues together at all,” he told reporters. “And I’m confident not only in our current position but in our prospective production rates as well.” It marked another instance of Hegseth and other Trump-era officials grumbling that the media were overstating munitions shortages.

The sentiment seems a bit rich. Warnings have been blinking for years about the United States’ capacity to gear up for future wars while backing proxy battles in Europe and the Middle East. The direct clash with Iran depleted U.S. magazines even more rapidly.

“The U.S. maintains stockpile requirements that align with contingency plans. Naturally, it accepts some risk when necessary,” explains Josh Paul, who previously served as a State Department official overseeing weapons sales. In other words, the question of how much ammunition is enough depends on how much danger the nation is willing to tolerate.

The shortages are particularly acute when it comes to air-defense rounds. This creates a risk profile unlike anything the U.S. and its partners have faced before. After decades of air superiority, the economics of modern warfare are exposing American troops—and Western societies—to aerial bombardment from adversaries.

The main phase of U.S.–Iranian fighting ended in April 2026, leaving 14 Americans dead and 409 wounded. There are signs the conflict could have escalated sharply if it had continued. Right before the ceasefire, Iran was achieving a higher hit rate with smaller salvos because the U.S. and its allies had exhausted so much of their air-defense ammunition. Israel was rationing advanced interceptors, with counts dipping into double digits, a U.S. source told Drop Site.

Future wars may resemble Ukraine more closely, with heavy bombardment on both sides, suggests Justin Logan, director of defense and foreign policy studies at the libertarian Cato Institute. “Americans like to insulate themselves and their friends from an opponent’s retaliation, but that approach is exceedingly costly.”

The shortages are already reverberating in Ukraine itself. After a June 2026 Russian air raid killed 22 people, Ukrainian President Volodymyr Zelenskyy urged European partners to accelerate deliveries of the American-made Patriot air-defense system, noting that the problem was no longer financial. There simply weren’t enough stocks to go around. Kyiv proposed “borrowing” Patriot ammunition from Germany—an emptying of German stores in exchange for an IOU.

Meanwhile, Taiwan awaits a $14 billion arms package that the Trump administration has already cleared legislatively. Part of the holdup appears political; President Donald Trump told Fox News the delay was “a very good negotiating chip for us” against China and a method to coax both sides toward calm. But shortages are another factor, Cao admitted. Reuters reports that the package, whose exact contents have not been made public, “largely consists of Patriot ammunition and other air-defense munitions.”

“Everybody wants to adopt the American way of warfare, but few can afford it, including us,” Logan notes. “The ability to sustain political backing erodes quickly when we can’t intercept retaliation.”

How Drones and Cheap Missiles Ended America’s Free Pass From Enemy Fire

For most of the last century, the United States grew accustomed to one-sided aerial campaigns. Before the recent Middle East conflicts, U.S. forces were last killed by hostile aircraft during the Korean War in 1953. In recent times, there was a sense that Washington could rain destruction on other states with little cost. Public attention drifted as the Obama, Biden, and Trump administrations waged “low-footprint” air campaigns around the world.

“It works for a while, when there’s a huge asymmetry, but adversaries of every stripe learn to adapt,” remarks Kelly Grieco, a fellow at the Stimson Center. “There were warning signs long before this war.”

A pivotal shift occurred with the drone revolution. Advances in electronics allowed small nations to join the fray by the early 21st century. Israel became a leading force in drone technology, which Turkey bought, and Iran later acquired. Chinese hobby drones hit civilian markets in the early 2010s, making this type of warfare even cheaper. The Islamic State even built a miniature “air force” by attaching grenades to photo drones.

During the 2014 Battle of Mosul against ISIS, an American colonel confided Grieco that he finally had to look to the sky and fear the enemy for the first time.

Meanwhile, Iran learned from Iraq—whose 1980 invasion of Iran led to a U.S. invasion in 2003—that it could not outpace a modern air force but could overwhelm with sheer numbers of ground-launched missiles produced domestically.

The decisive turn may have come in the 2020 war between Azerbaijan and Armenia, when Azerbaijani forces introduced Israeli “kamikaze drones” that steer into targets and detonate, complemented by Turkish conventional drones. Two years later, when Russia invaded Ukraine, the Ukrainian army invested in those same Turkish drones, while Russia imported Iranian experts and designs to mass-produce the Shahed 136 kamikaze drone.

As the war in Ukraine dragged on, both sides embraced what the Islamic State used to do—utilize hobby drones to drop grenades on individual soldiers. When radio interference made drone assaults harder, armies began equipping their drones with fiber-optic lines. Battlefields became littered with miles of discarded cables. Beyond the front lines, Russia and Ukraine have employed long-range drones to strike at each other’s infrastructure, and drone forces to counter or shoot down those attackers.

The United States and its Middle Eastern partners had grown accustomed to higher levels of protection than Russia or Ukraine could achieve. Israel’s Iron Dome, designed for short-range rockets and artillery, reportedly intercepted about 90 percent of incoming threats in various conflicts from 2011 to 2023. The oil-rich Gulf monarchies were even more risk-averse. When Yemeni rebels struck Saudi Arabia with drones in 2019 and the United Arab Emirates in 2022, those strikes provoked national crises.

This year’s conflict with Iran unleashed the first sustained aerial assault on those states by a more capable opponent than irregular guerrillas. They attempted to preserve their previous insulation, but at a massive cost. Ukrainian military advisers told The Times of London that they were “astonished” to see Arab armed forces firing eight Patriot interceptors to take down a single Iranian drone. Israel reportedly expended 80 percent of its entire stockpile of advanced Arrow interceptors in just 16 days, according to a study by the Royal United Services Institute (RUSI) in Britain. On top of that, the U.S. military deployed more interceptors in Israel’s defense than the Israeli army itself did, per The Washington Post.

The Israeli and American militaries also consumed large portions of their offensive arsenals, according to RUSI. Hegseth warned Japan that the U.S. could no longer spare Tomahawk cruise missiles, the Financial Times reported. When the U.S. runs low on these “standoff munitions” that enable distant strikes, the conflict must move closer to the threat, which raises risk, Grieco notes.

A key factor in the Iran miscalculation was the expectation of a swift triumph. Trump publicly and privately anticipated Iran’s collapse within days. Early in the war, the military boasted of proactive steps to suppress Iranian missile fire in the short term by hitting launcher trucks or collapsing underground bases. But the launchers proved easy to replace—they’re essentially trucks with added hydraulics—and the base entrances could be excavated again.

The most concerning near-term scenario for the U.S. armed forces would be a conflict with China in the Pacific, combining all these challenges with new dimensions. U.S. allies—Japan, South Korea, and Taiwan—are high-tech economies within range of Chinese and North Korean missiles. China’s air defenses are far more robust than Iran’s, making missile suppression nearly impossible. And because Taiwan is an island, all of its defensive weapons would need to be imported before a crisis begins.

In January 2023, the Center for Strategic and International Studies (CSIS) ran a war game simulating a Taiwan invasion. The simulation showed the U.S. military would exhaust its Long Range Anti-Ship Missiles (LRASMs) within days and its Joint Air-to-Surface Standoff Missiles (JASSMs) within two to three weeks. The center concluded that the United States could repel an invasion, but at the cost of hundreds of aircraft—and more American casualties in a month than had occurred in the previous generation of wars combined.

Why the Pentagon Can’t Simply Build Its Way Out of the Ammunition Crunch

After three years of fighting in Europe and the Middle East, the ammunition situation has deteriorated substantially. The U.S. military expended roughly a quarter of its JASSMs in the Iran conflict, according to a RUSI study. A separate CSIS report from May 2026 estimated that reconstituting those missiles could take until mid-2027; restoring various air-defense magazines to prewar levels would require another two years, and replacing all Tomahawk missiles used in the war would stretch into the 2030s.

The Pentagon aims to invest enormous sums to fix this. The fiscal year 2027 budget request, a historic $1.5 trillion, includes about $52 billion for high-priority munitions—almost five times higher than the prior year—and another $100 billion to rebuild the industrial base. In addition to the annual defense budget, the Trump administration also planned to seek Congress’s approval for $200 billion in supplemental Iran-war funding, though that request was later trimmed and folded largely into the regular budget, according to The Washington Post.

A closer look at the budget reveals how lopsided the logic of air defense spending is. The latest Patriot interceptor model, the PAC-3, costs around $4 million per unit. (Arab militaries reportedly fired up to eight interceptors for a single drone.) While the Shahed 136’s exact price is not public, an Iranian source told Phenomenal World that each drone costs about $4,000 in direct currency, after adjusting for local costs and labor.

More crucial than the sticker price are the resources and time required for production. Phenomenal World calculated that the true cost of a Shahed 136, including production inputs, would be around $7,000 per drone—still far cheaper than an interceptor designed to shoot it down. A single Shahed factory in Russia can produce about 5,500 drones per month, but the total annual PAC-3 output is currently under 1,000. In the two-year order-to-delivery cycle for a PAC-3, new workers must be trained in specialized skills and cleared for security; Lockheed Martin must source components from more than 400 suppliers.

The PAC-3 frequently competes with other weapons for the same components—and those parts compete with other industries and other nations for raw materials. In April 2025, China imposed strict export controls on rare-earth minerals and permanent magnets, pushing the Pentagon to search for new sources, according to CSIS.

Private investment can raise production. The United States and its allies have had some success in boosting the output of 155mm artillery shells, one of the main concerns two years ago. Still, expanding production takes time. Lockheed Martin plans to raise PAC-3 annual production to about 2,000 units by fiscal year 2030.

The extended payoff period for such investments is a structural hurdle. “The challenge has always been whether the private sector is willing to reinvest profits into production,” says Paul, the former State Department official. “If you’re a public company, would you prefer a full 10-year forecast, or commit your own capital to build a new plant that could reduce your book value for a decade, for a system that might become obsolete in a decade?”

Despite these obstacles, the United States remains the world’s leading arms supplier. Its share of the global market has actually grown since 2016, according to the Stockholm International Peace Research Institute. When asked whether the United States has enough munitions, Grieco consistently replies that it depends on what you intend to do; “Sufficient munitions to do what? Because no country, perhaps except China, has this kind of depth in munitions.”

Ultimately, the challenge with munitions isn’t merely a supply shortfall but rather an imbalance between demand and capacity. The United States seeks to be involved in conflicts around the world while maintaining the ability to spark new ones, such as Iran, and societies like ours have tended to assume punishment would be avoided in warfare, Logan contends.

That stance isn’t sustainable in light of advances in missile and drone technology. “Warfare now favors large quantities of smaller, cheaper, plentiful assets that favor defense,” Grieco notes. Ironically, the abundance of offensive tools means defenders can more effectively punish an attacker.

Rather than attempting to reverse this trend, the United States could stop placing itself in the role of aggressor. Washington’s principal foreign-policy aims outside the Middle East include repelling any invasion of Ukraine and deterring one against Taiwan. If the U.S. can resist the urge to embark on further wars, these technological shifts “should be good news,” Grieco argues. “We should be leveraging this defensive potential.”