David vs. Goliath: Cost Asymmetry in Warfare

Dramatic images of million-dollar missiles streaking into the air to intercept low-cost drones have filled our television screens for three years, amid fighting in Ukraine, Israel, Gaza, and the Red Sea.

While cost asymmetry has always played a role in tactical warfare, we now face more strategic questions because it is so cheap to attack and so expensive to defend.

U.S., European, and Israeli air and missile defenses have performed remarkably well in these conflicts. However, with the technical sophistication of these systems comes a hefty price tag. Now, the advent of cheap commercial drones has sharply tilted the cost asymmetry towards offense.

A Frugal Method of Destruction

New threats include so-called kamikaze systems such as the Iranian Shahed, used widely by the Russians and Houthis, as well as modified commercial first-person-view (FPV) drones, many of which are manufactured in China and can be purchased by anyone online.

These are being employed in staggering numbers by both sides in the war on Ukraine. On their own, their capabilities may be crude, especially compared to a traditional fighter aircraft or long-range precision-strike missile. Still, “quantity has a quality all of its own.”

Wielding such new weapons, attackers aim to wear down sophisticated defenses. They do so by cluttering and confusing the sensor picture, burning through defenders' finite stocks of expensive missile interceptors, and forcing high-value assets such as air defense batteries to reveal their positions by illuminating their radars or firing.

This opens defenders up to subsequent attacks or, at the very least, compels them to relocate, creating gaps in the defenses during the move.

These new threats also place enormous strain on government finances and industrial supply chains responsible for replenishing depleted missile stockpiles. Both the United States and Europe have struggled for two years to increase production rates for air defense systems and missiles after three decades of low investment in the manufacturing base.

Throwing Money at the Problem

In January 2025, the U.S. Navy disclosed that it has fired more than 200 missiles to repel Houthi attacks on civilian shipping in the Red Sea since November 2023, at a cost of hundreds of millions of dollars.

This includes 120 SM-2 missiles priced at around $2.1 million each, eighty SM-6 missiles at $3.9 million apiece, and twenty Evolved Sea Sparrow and SM-3 missiles estimated to cost between $9.6 million and $27.9 million each, as well as 160 rounds from 5-inch naval guns.

Of course, the comparison is not as simple as measuring a million-dollar interceptor against a thousand-dollar drone.

When a NATO destroyer engages a drone or missile in the Red Sea, it does so to prevent it from hitting a military target, thus killing sailors and damaging equipment worth hundreds of millions of dollars, or striking an unprotected civilian ship, creating the risk of environmental disaster if an oil spill occurs.

Houthi disruption in the Red Sea has already cost the global economy and financial markets hundreds of billions of dollars, so mitigating this threat with a few missile interceptors can represent a good return on investment.

Militaries are therefore seeking ways to tip the economic calculus back in the defender's favor. The U.S. and British navies, for example, are exploring the possibility of re-arming missile tubes at sea, a first-time endeavor, to reduce the time, money, and fuel required for ships to return to port after expending their munitions.

They are also racing to expand electronic warfare capabilities to jam, spoof, blind, or confuse incoming drones and munitions.

Perhaps most ambitiously, they are experimenting with high-powered lasers and microwave weapons. These directed-energy systems, once the stuff of science fiction, offer the prospect of a low-cost way to destroy targets within the weapon's line of sight. Following a recent test of its DragonFire laser system, the UK Ministry of Defense claimed that it cost just twelve dollars USD per shot to down aerial targets such as small drones and mortar rounds, despite the $120 million spent on development.

Beyond active defenses, militaries are pursuing more passive measures to reduce the threat and expense of hostile air, missile, and drone strikes. Examples include dispersing forces, employing camouflage and decoys, and investing in fortifications or backup systems to minimize the impact of attacks.

Alongside punitive retaliation, these tactics aim to deter and disincentivize attackers, shifting the cost-benefit calculation in the defenders' favor.

In addition to the many ways of dealing with threats “right of launch,” when enemy drones or missiles are airborne, there is renewed interest in addressing them “left of launch,” before they can be enacted.

Lessons can be drawn from the fight against improvised explosive devices (IEDs) in Iraq and Afghanistan. In those theaters, Western forces not only enhanced the IED protection of their vehicles but also targeted the supply chains, training pipelines, and organized terror networks that built and deployed IEDs.

Combined Effort Is Needed

Ultimately, there is no “silver bullet” solution. The United States and Europe must work together urgently to build a broader toolkit of defensive options. This entails layered and integrated air and missile defense, a “high-low mix” that combines advanced solutions, such as Patriot missiles, with novel, more affordable methods of tackling swarms of low-cost quadcopters.

Defenders must also explore new ways to impose costs on adversaries, whether by deterrent measures or by undermining the supply chains and expertise that enable actors to acquire capabilities such as suicide drones.

While it may be impossible to halt the proliferation of these systems outright, it is possible to increase the cost of doing business for states and groups like Russia, China, Iran, or the Houthis, and to reduce the likelihood of successful attacks, making them think twice before launching.

Such measures are urgently needed to counter threats on Europe's and the Middle East's battlefields today, and to prepare for potential conflicts in the Pacific (i.e. Taiwan) shortly.

War is an expensive enterprise. The vital question is who can, and will, shoulder most of those costs, and who can make it too expensive for their adversaries to continue the fight.