Magazine depth has suddenly become one of the most fashionable phrases in national security. Turn on the news, read an article about Ukraine, the Red Sea, Iran, or a potential conflict with China, and the question appears almost immediately: Do we have enough interceptors?

It is an important question. It is also the surface of a much deeper problem.

The more interesting question is how the most technologically advanced military in the world, with decades of warning, unmatched intelligence capabilities, and generations of experienced leaders, arrived at a point where the depth of its defensive magazines has become a strategic concern.

The answer is not that anyone forgot missiles could fly. It is that successful institutions make assumptions. They begin influencing requirements, budgets, organizations, acquisition programs, and career opportunities. The danger comes when an assumption lasts long enough to become culture. Culture becomes force structure. Force structure becomes capacity. And capacity determines the choices available when the assumption finally fails.

For decades the United States enjoyed something historically extraordinary: American forces could generally assume that the sky above them was safe. We knew intellectually that air and missile threats existed. But intellectually understanding a threat is different from organizing a military as though that threat may determine whether you survive.

So what happened?

Nothing new under the sun

There is nothing particularly new about threats arriving from above. For thousands of years, militaries have adapted to weapons that allowed an enemy to strike from beyond immediate reach. Arrows encouraged shields, body armor, dispersal, and formations designed to reduce vulnerability to massed projectiles. Technology changed. The underlying problem did not.

When aircraft emerged as weapons during the First World War, Britain discovered how poorly prepared it was to defend its homeland against them. British home defense had traditionally focused on the coastline. German Zeppelins and later Gotha bombers suddenly created an entirely different problem.

The response was adaptation: observers, searchlights, anti-aircraft guns, fighters, new ammunition, communications networks, and eventually more integrated systems for detecting, tracking, and defeating incoming raids. The Imperial War Museum describes Britain at the beginning of the war as “ill-prepared” for the aerial threat; successive raids forced the country to build the defenses it had not expected to need.

During World War II, Britain developed a remarkably sophisticated integrated air-defense system combining radar, observers, command and control, fighters, anti-aircraft guns, searchlights, and barrage balloons. The strength was not any single weapon. It was the system connecting them.

Then the Germans changed the threat. The V-1 flying bomb required another adaptation. Fighters, anti-aircraft artillery, and balloons destroyed thousands of them. The V-2 then arrived at speeds that made interception effectively impossible with contemporary technology, shifting the problem toward attacking launch infrastructure and disrupting the system producing and employing the weapon.

This illustrates one of warfare’s oldest cycles of adaptation and we should not be surprised that the modern battlefield once again contains threats from above. Hollywood seems to understand it. When the enemy shows up with dragons, somebody comes up with a very large crossbow.

Given all of this precedent, both fact and fiction, repeatedly convincing ourselves that the latest period of sanctuary will last is increasingly difficult to defend.

When an advantage becomes an assumption

The United States emerged from the Cold War with overwhelming conventional military superiority and Desert Storm appeared to validate it. American airpower dismantled one of the world’s larger militaries while establishing an expectation that U.S. ground formations would operate underneath friendly control of the air.

That advantage became even more pronounced during two decades of war after September 11. American soldiers fought extraordinarily difficult campaigns in Iraq and Afghanistan. They faced improvised explosive devices, ambushes, snipers, rockets, mortars, suicide attacks, and an adaptive enemy. What they generally did not face were hostile aircraft routinely attacking maneuver formations.

Ports were not being struck by massed precision missiles. Airfields were not subjected to sustained campaigns designed to crater runways and destroy aircraft on the ground. Logistics hubs operated without hundreds of long-range weapons arriving simultaneously.

That experience mattered as organizations optimize around the problems they repeatedly encounter. The Army needed infantry formations. It needed intelligence personnel, special operations forces, route-clearance capabilities, aviation, logistics, headquarters, trainers, advisers, and countless other specialties required for Iraq and Afghanistan. Something had to pay the bill.

Air defense was one of those things.

This was not irrational. Decision makers were solving the problems directly in front of them. A service chief deciding that another maneuver formation was more valuable than another patriot battalion might have been making exactly the right decision for 2006. A programmer accepting slightly more air-defense risk to fund an urgent wartime requirement might also have been right. A personnel system sending talent toward expanding communities rather than shrinking ones would have been behaving logically. An acquisition executive purchasing relatively modest quantities of expensive interceptors when combat expenditure was low would have been acting rationally. Industry declining to build enormous excess production capacity without corresponding government demand would have been rational too.

No one person made a catastrophic decision. Thousands of individually defensible decisions accumulated into strategic vulnerability.

We burned more than missiles

The Patriot force is an especially useful illustration.

The previous Army Vice Chief of Staff General James Mingus said in 2025 that Patriot was the Army’s “most stressed force element.” The Army had 15 Patriot battalions, but one was undergoing modernization, leaving 14 available. Three were assigned in the Indo-Pacific, one in Europe, and one Patriot battalion in CENTCOM had been there for close to 500 days.

Air defense is not simply an inventory of missiles. It is a force of crews, radars, launchers, maintainers, command posts, and training pipelines. It is families absorbing repeated deployments and experienced captains and majors deciding whether they want to remain in the community. It depends on battalion commanders, industrial capacity, geography, and ultimately, time. 

You can place money into a budget for the out-years. You cannot instantly create an experienced air-defense battalion commander. That is a human-capital problem far beyond what money, or a memo, can solve.

A study published by Army University Press surveyed every active-duty Air Defense Artillery major and lieutenant colonel, 409 officers in total. Two hundred fifty-four responded, a remarkable 62 percent response rate. The study examined a troubling phenomenon: whether ADA officers wanted to compete for battalion command. Officers declining command consideration repeatedly cited family stability, retirement plans, burnout, and the extraordinary operational tempo of the air-defense force. The study describes ADA as facing a genuine battalion-command challenge at precisely the moment when the Army needs to expand the community.

That is not an interceptor problem.

Culture is a strategic choice

If you want to know what an institution values, look at where it puts its people.

What signals did the Army send its talent about the relative importance of air defense? For nearly three decades in uniform, I watched generations of officers make career decisions. Every military institution develops hierarchies of prestige.

Young officers notice which branches their classmates compete for, which assignments senior leaders praise, which organizations produce prominent commanders, and where opportunities appear limited. No regulation needs to say one branch is “cooler” than another. Culture handles that efficiently.

When the operational environment repeatedly treats a capability as peripheral, the institution eventually absorbs the message. And when strategy suddenly declares it indispensable, culture cannot reverse itself overnight.

For a harder measure, look at where the Army's most successful and talented air-defense officers can go; there simply are not many places for them. Few senior commands, few senior staff positions, and almost no path into the Army's broader leadership. In an up-or-out institution, they compete for talent, resources, and attention against communities with far greater institutional weight.

General James Dickinson illustrates both an exception and the limitation. A career air defender, he became the first ADA officer to reach four stars and command U.S. Space Command. But even his path says something about where the institution believed the highest-order threat was headed and where its talent needed to go. Space.

Institutional weight matters. It shapes who is at the table when a massive organization decides what it needs, what it can afford, and what risk it will accept. Who was arguing for another Patriot battalion, or deeper interceptor magazines when those requirements competed against more immediate priorities? When drones, cruise missiles, rockets, loitering munitions, and other inexpensive threats proliferated across the battlefield and beyond it?

We are now living with the result. The shortage, the confusion over what to buy, who should buy it, how fast to field it, and how it all fits together.

The illusion of coverage

Before Russia’s full-scale invasion of Ukraine, NATO possessed sophisticated command-and-control architecture for ballistic-missile defense. Ramstein played a central role in that architecture. In a 2012 test, NATO’s command-and-control system at Ramstein linked German and Dutch Patriot batteries, a U.S. Aegis destroyer, early-warning systems, sensors, and command elements across Europe and North America.

That sounds formidable. But testing architecture is not the same thing as developing unlimited defensive capacity against complex threats of the future.

The distinction became further evident when Turkey requested additional missile defense because of the Syrian threat in 2012. Germany, the Netherlands, and the United States each contributed two Patriot batteries, for six total. The American contribution required moving Patriot forces into Turkey. Later rotations brought two batteries from Germany to sustain the mission. Again, the point is not that NATO lacked air defense. The point is scarcity. A Patriot battery defending one location cannot simultaneously defend another.

Now imagine the requirement in a conflict with Russia understanding what we do now about the reality of modern warfare.

Ramstein. Bremerhaven. Rotterdam. Air bases. Ports. Ammunition depots. Fuel farms. Railheads. Headquarters. Logistics concentrations. Bridges. Power infrastructure. Maneuver formations. Each is important. Many are vulnerable. Some are hundreds of kilometers apart. How many receive Patriot? How many receive another system? How many receive nothing?

The recent discovery of an armed drone in Germany is yet another reminder that these vulnerabilities are no longer confined to distant battlefields or ballistic missiles. This underscores the increasingly complex challenge of protecting aerial and seaport points of debarkation (APODs and SPODs)—the critical nodes that truly enable American projection. Those facilities are more than logistics hubs. They are an essential strategic foundation of U.S. military global power.

The ability to reinforce Europe, sustain allies, or project combat power ultimately depends upon the infrastructure that makes global reach possible, not just magazine depth.

Red Sea in the morning… sailors take warning

If Ukraine demonstrates that massed air and missile threats had returned to land warfare, the Red Sea gives the U.S. Navy an extraordinary real-world live-fire experiment in defensive consumption.

According to figures cited by the Congressional Research Service, over roughly 15 months the Navy’s surface fleet fired nearly 400 defensive munitions in the Red Sea fight. That included approximately 120 SM-2 missiles, 80 SM-6 missiles, 160 five-inch rounds, and a combined 20 Evolved Sea Sparrow Missiles and SM-3s.

The good news is Aegis worked. Standard Missiles worked. The Evolved Sea Sparrow worked. Navy crews detected, tracked, and destroyed drones, cruise missiles, and ballistic missiles in combat. Tactically, our performance has been impressive. Strategically, it should make us uncomfortable. The Houthis became dangerous to the U.S. Navy and still remain dangerous. A non-state adversary generated enough threat density to require approximately 200 SM-2 and SM-6 launches in about fifteen months.

Now put that against the pacing threat.

The pacing problem

The Department of Defense assesses that the PLA Rocket Force possesses more than 900 short-range ballistic missiles, roughly 1,300 medium-range ballistic missiles, approximately 500 intermediate-range ballistic missiles, and about 400 ground-launched cruise missiles.

Those figures do not include every weapon China could employ against American forces. Nor does China likely intend to launch missiles randomly. Its force has been built around a concept designed to complicate U.S. intervention by threatening the things American military power requires to function.

This is where “magazine depth” becomes almost an inadequate phrase.

The United States unquestionably retains the ability to impose devastating costs on adversaries, to paraphrase comments made by USPACOM Commander Admiral Paparo, "we have game too." But one must always consider the decisions commanders will face during the hours and days of a high-end conflict.

If a multimillion-dollar interceptor is the weapon available to stop a comparatively inexpensive threat from destroying a billion-dollar asset or killing American servicemembers, does the commander shoot? Of course.

This is an issue clearly identified and many are working to address. That does not mean the strategic resources available to make those decisions are yet adequate. Nor does all the fervor about shooting million-dollar missiles at hundred-dollar drones mean change can happen overnight.

Winning every engagement and still having a problem

Magazine depth discussions often focus on the unfavorable economics of firing expensive interceptors against cheaper weapons.

Can Patriot intercept a ballistic missile? Yes. Can Aegis defeat sophisticated airborne threats? Yes. Can modern short-range systems and emerging technology destroy various sizes and types of drones? Yes. Those are engineering questions.

The strategic questions are different. How many? For how long? Against what raid density? In how many places simultaneously? How quickly can they be reloaded? How rapidly can industry replace what was fired? How many crews can sustain the operational tempo? And what happens when the adversary deliberately designs its campaign around exhausting the defender?

The Red Sea demonstrated that a force can perform exceptionally well tactically while simultaneously exposing a structural vulnerability. American warships repeatedly defeated the weapons fired at them. Their success generated the data we now find troubling.

That is not a contradiction. It is a lesson.

Assumption debt

There is a concept in the technology industry called technical debt.

A company makes a decision that solves an immediate problem but creates an obligation that eventually must be addressed. The military accumulates something similar. Assumption debt.

The assumption begins reasonably. American air superiority is overwhelming. It remains overwhelming. Year after year passes. Ground forces deploy without facing hostile air attack. Ports function. Airfields function. Ships operate with manageable defensive expenditures. Patriot demand remains high but bounded. The assumption survives another budget cycle. And another. Eventually, nobody needs to explicitly decide that the assumption is permanent. It becomes embedded. Requirements reflect it. Force structure reflects it. Industrial production reflects it. Training reflects it. Personnel policy reflects it. Career incentives reflect it. The institution begins optimizing around yesterday’s successful experience.

Then, as both history and Game of Thrones have warned, the environment changes.

Russia employs missiles and drones at scale. Ukraine improvises an extraordinary drone ecosystem of its own. Iran demonstrates increasingly sophisticated long-range strike capability. The Houthis forced the U.S. Navy into sustained defensive combat. China builds one of the world’s largest and most sophisticated missile forces. Suddenly the assumptions embedded across multiple decades come due simultaneously.

But magazine depth, which we hear about now, is not where the story began. It is where the consequences became visible.

The human variable

It is tempting to look backward and blame the people who made these decisions. That would be easy. It would also miss the point.

The people making those decisions were often right. The Army really did need manpower for Iraq and Afghanistan. The Navy really did face competing modernization requirements. Congress really did have finite resources. Industry really could not economically maintain production lines for weapons governments were not ordering. Commanders really did operate for decades beneath overwhelming American airpower.

The problem was not stupidity. It was human nature interacting with institutions.

We tend to provide more weight to recent experience and become increasingly confident in assumptions that repeatedly prove correct. We discount risks that haven’t occurred. We reward people who solve visible problems and invest in capabilities producing measurable effects. All while we struggle to assign equal value to those whose greatest achievement is that nothing happens.

An air defender may perform perfectly for an entire deployment and never fire a missile. A cyber defender may prevent an attack nobody knows occurred. An intelligence organization may prevent a surprise that therefore never happens. A logistician may create a system so resilient that nobody notices logistics. Prevention rarely produces the same institutional mythology as visible victory.

Until prevention fails.

This is a human-capital problem as much as a procurement problem. Experience has to be grown. Trust has to be built. Institutional prestige develops slowly. Families absorb the cost of deployments. Officers decide whether the career remains worth pursuing. NCOs decide whether to reenlist. And industry makes long-term investment decisions based on whether government demand looks durable or temporary. Every one of those choices contains a human being making what appears to be a rational decision.

That is how assumption debt accumulates.

Air defense is not just interceptors

If we define the problem primarily as insufficient interceptor inventory, we may solve it too narrowly. Effective air defense has almost never consisted solely of shooting down whatever arrives.

Britain's World War II defense integrated radar, observers, command and control, fighters, guns, searchlights, balloons, deception, civil defense, and attacks against enemy systems.

Modern defense doctrine must be at least as broad. That means destroying launchers, disrupting targeting and production, blinding sensors, jamming navigation, and attacking command and control. It also means dispersing forces, hardening installations, building redundancy, deceiving the adversary, and integrating civil and private defense systems. Use inexpensive weapons against inexpensive threats when possible and save exquisite interceptors for the threats that require them. Then intercept what gets through. The solution, in other words, is a mix of capabilities, not the technology or company that happens to command attention today.

There is also a danger that today's investment cycle becomes narrowly focused on the technologies and companies promising the fastest answer.

Every generation produces its favored technology, its favored companies, and its favored narrative. Those innovations deserve attention, but influence, investment, and headlines do not necessarily equate to strategic solutions. Some will prove transformative. None will solve the broader challenge alone. Air and missile defense is not a single technology problem. It is a systems problem built on integrating complementary capabilities, not replacing them.

The objective should not be to build an infinitely deep magazine. No magazine is infinitely deep.

What are we assuming today?

The easiest problems to address are now visible because we can measure them. We can count interceptor inventories, production rates, Patriot battalions, vertical-launch cells, and factory capacity. We should address all of them. But if the only lesson we take from this is that America needs more munitions, we will have learned too little.

An even harder lesson concerns how we got here.

This may be the most dangerous part. Because the question is not merely what assumption the last generation got wrong. The question is what assumption we are making right now that the next generation will find is equally inexplicable.

Perhaps it is access to our supply chains or bases, space, cyber infrastructure, commercial communications and logistics, tanker survivability, ports, undersea infrastructure, or industrial capacity. Maybe it is something receiving so little attention today that it sounds ridiculous to put on that list. Or perhaps it is something we currently consider too invincible to fail.

This summer, during President Trump's departure from Turkey, U.S. security officials reportedly confronted a credible threat involving a shoulder-fired missile against Air Force One. The response included an extraordinary aircraft switch, deception, and the covert movement of the president to another military aircraft. One person's shoulder was enough to alter the movement of the President of the United States and threaten our continuity of government. The air-defense problem exists across the entire threat spectrum, and we do not get to choose which end matters.

Strategic vulnerability is built. One reasonable decision at a time.

You Can't Surge What You Didn't Build

The Pentagon’s most recent senior-level response provides an almost perfect illustration of the limits of urgency. Deputy Secretary of Defense Steve Feinberg directed defense companies to return within 21 days with plans to significantly accelerate production and delivery of critical weapons. The urgency is justified. We should build more, and faster. But urgency is not capacity. Short of extraordinary wartime mobilization, even authorities like the Defense Production Act cannot simply order an industrial base into existence.

A memorandum can change priorities. It cannot immediately create skilled workers, energetics capacity, rocket motors, seekers, suppliers, test facilities, or production lines. Nor can all the startups, venture capital, and enthusiasm pouring into defense technology instantly replace industrial capacity we spent decades allowing to atrophy. Innovation matters. New entrants matter. But as an old special operations adage warns, never confuse enthusiasm with capability.

Industry built largely against the demand the government created. Now the government is demanding more, faster. But urgency does not erase decades of choices or recreate capacity overnight.

We need to rebuild the magazines. We also need to fix what emptied them.

The Danger of Being Right

This current national-security predicament is also a cautionary tale well beyond government. Assumption debt is not unique to the military. Companies, boards, and other institutions allow successful experience to harden into assumptions about capital, supply chains, technology, talent, and risk. The longer those assumptions prove correct, the more deeply they become embedded and the harder they are to challenge.

The danger is that others are always looking for them. Our adversaries study the assumptions built into our force and search for ways to exploit them. Competitors do much the same in business. What looks internally like a reasonable risk assumption may look externally like a strategic opportunity.

The lesson is to challenge assumptions before circumstances do it for us. Build mechanisms that force organizations to revisit what they believe, identify where those beliefs have become structural commitments, and recognize when yesterday's advantage is becoming tomorrow's vulnerability.

That is why magazine depth is more than a defense problem. It is a warning about how successful organizations can create vulnerability without realizing it.

But magazine depth was never the story

Magazine depth is a real problem. But it is the visible consequence of decisions made years before anyone started talking about it, and it was perfectly predictable.

We absolutely should build more interceptors, and faster. But we cannot manufacture our way out of the larger problem that got us here. If the conversation stops at how many interceptors we need or how quickly industry can produce them, we have kicked a can down the road. The more important discussion is why we arrived here in the first place, and what government, the military, Congress, and industry must do differently, from how we define requirements and accept risk to how we fund, build, and sustain the force, so we are not having this same conversation twenty years from now, when Patriots themselves may be ineffective.

Sometimes the answer will be more interceptors. Sometimes it will be a new system, a different organization, or a novel way of thinking about the threat. And apparently, sometimes the best air-defense solution available may even be a covert aircraft catering truck.

Offense has always had an institutional advantage. F-35s, aircraft carriers, special operations forces, and even ideas like orbital bombardment promise initiative, decisive action, and taking the fight to the enemy. Defense asks us to spend enormous resources so that something does not happen. One naturally attracts attention, talent, resources, and prestige. The other gets attention when something gets through.

That is why air defense isn't sexy. 

Until it is.