This isn’t a technology problem. It’s a math problem. And the math is merciless. It is no longer the question of whether a radar can be able to see a target or whether an interceptor can strike it or not. It is characterized by the ability of a defender to afford to continue shooting. Since uncrewed aircraft are increasing in number, particularly in a coordinated attack where expendable drones are used to confuse and distract defenses, every successful intercept may mean a strategic loss of both cost and capability. That is, a defender will be in a position to win the engagement and lose the campaign.
When high end missiles are assigned low end problems, the cost curve manifests itself best. The head of the acquisition department of the Pentagon has been quoted saying that there are instances in which drone interceptions are costing over 100,000 dollars per shot, and that common naval and ground interceptors are much more expensive. That discussion had a simple goal: make the price of a defensive shot down to the “tens of thousands” range, possibly even down to $10,000, since the existing level of exchange can not be sustained.
Swarm logic is based upon that exchange rate. A drone will not require penetration to be attractive; it simply requires forcing a decision. By launching few missiles in defense, the defenders waste Magazine depth, logistic energy, and training time on targets that are fast generated, fast replicated, and launched in large numbers. A defender may be raced in replenishment speed and unit economics, even when he is shooting ideally: in particular, raids that are meant to do ambiguity effects rather than precision effects.
Clutter and decoys enhance the issue by violating the sensor-and-shooter loop of the defender. Contemporary decoys are developed to present visual, thermal and radar signatures, i.e. to appear as an actual weapon, which implies that they are designed to draw as much defensive attention as an actual weapon. A study published in that analysis indicates that a one-to-one ratio of real and decoy targets can increase survivability by 40 percent, but the proportions of decoy target can cause a steep increase in the consumption of enemy munitions. The concept is simple: the fake targets lead to the track loading, burning more “looks” and exposing the expensive interceptors to the waste of attacking objects that were not supposed to hit anything. A one short paragraph is important in this context: air defense is a budget as much as it is a weapon.
The recent focus on drone-on-drone interception in Ukraine shows the attempt by defenders to reverse the mathematics of the problem. Coverage of interceptors manufacturing said that production was nearly 950 units per day and had these devices bringing over 1,500 drones down, with more advanced missiles in reserve against more serious threats. Even a field commander in the same quote underlined the infrastructure stakes: Every destroyed target is something that did not hit our homes or power plants, said a commander who is identified by the call sign Loi. It also quoted a measured success rate of interceptors of 68 percent, which is significant since economics can afford losses in case the shot is cheap and abundant.
The trends in industry and procurement are coming to one and the same conclusion: the defeat mechanisms should become cheap, quick to produce, and not hard to multiply. A tour of low-cost kinetic effectors, provides an emerging ecosystem of choice UAV interceptors that ram targets, warhead-toting variations, repurposed guided rockets, and micro-scale, purpose-built counter-UAS missiles each attempting to offer acceptable probability of destroy without bringing the entire cost-structure of conventional surface-to-air weaponry. The cost per-shot versus cost per-engagement dilemma is also considered by designers in this “low-cost” category, since sustained defense is eventually a throughput issue: detection, identification, assignment and sufficient cheap rounds to outlast the raid.
The reason why cheap swarms continue to win is that they regard air defense as accounting with physics attached. The defender must commit the certainty to overcome the uncertainty-firing at tracks which may or may not be real, may be decoys, may be there to generate the most costly response of all.
