Iran’s missile campaign exposed the limits of Western deterrence

On 28^th February, 2026, Iran launched Operation “True Promise-4,” a wave of ballistic missiles and drones into Israeli airspace. The strikes were in response to the US and Israeli attacks on Iranian territory, which saturated the most heavily protected skies until even success became unaffordable for their adversaries.

Iran went into the war with the most sophisticated ballistic missile arsenal in the Middle East, including the solid-fuel Fateh family, hypersonic-adjacent Fattah-1 and older Shahab-3 variants. It fired over one hundred heavy missiles in each wave; analysts called it “volumetric saturation”– overwhelming the target with more missiles than any interceptor network could handle. Israel’s Iron Dome, David’s Sling and long-range Arrow defence systems had created the most multi-layered air-defence system ever deployed. However,

Israel had used approximately 81 per cent of its Arrow interception units before the war ended. This was not because of a failure of the system, but simply because there was no defensive architecture that can withstand such saturation for an extended period of time.

Iran’s more recent solid-fuel rockets, such as the Fattah-1 and Kheibar Shekan, were intentionally integrated with older, low-cost liquid-fuel missiles. This was not redundancy; it was design and strategy. The newer missiles do not technically qualify as hypersonic glide vehicles but have manoeuvrable re-entry vehicles which can jink at speeds over Mach 5 during the terminal phase, making it difficult to intercept by systems like THAAD and Arrow. Legacy missiles, meanwhile, tend to serve as expendable decoys, which compels the defender to use high-cost interceptors to counter low-cost projectiles. Early March strikes against Tel Aviv and Ben Gurion airports, followed by salvoes over northern and central Israel, have been assessed by open-source intelligence to be fired from cluster-type payloads on systems like Khorramshahr-4. Reportedly, these systems have dispersed approximately 80 submunitions over a broad area, a tactic used to maximise the damage under a strained interception capacity.

Not even the US airpower was completely shielded. For instance, a US F-35 jet conducted an emergency landing after being hit by Iranian fire during a combat mission.

Though Iran did not prevail militarily, it proved that a state under decades of sanctions and lacking a sophisticated Airforce could still create significant attritional pressure on a technologically superior coalition through saturation attacks and cost imposition asymmetry.

This was not just a battlefield anecdote but a doctrinal shift.

The clearest evidence lies in Washington’s own ledgers. During Operation Epic Fury, the United States launched over a thousand Tomahawk class cruise missiles and up to two thousand advanced interceptors. Costing approximately USD 15.5 million per interceptor, THAAD was used at a rate of somewhere between 150 and nearly 290 units, accounting for more than half of the system’s pre-war national inventory. Before the war, there were reportedly just 3,000 to 4,500 missiles in reserve — nearly a quarter of America’s arsenal used in a single war against a non-peer foe. Secretary of State Marco Rubio pointed out that Iran had manufactured more than a hundred missiles per month, while the US has been manufacturing no more than a handful of interceptors in the same period. Centre of Strategic and International Studies (CSIS) now estimates that it would take until late 2029 to restore THAAD inventories alone. In fact, the Pentagon’s FY2027 budget request for 785 more Tomahawks is an admission that the war was not a temporary inconvenience, but rather a structural vulnerability. That vulnerability does not stay contained. These depletions have also caused the Pentagon to rethink its Taiwan contingency plan due to concerns that diminished stockpiles would not be enough to maintain deterrence in both theatres. Throughout this period, China has been accelerating its missile arsenal and area denial systems while also keeping an eye on the numbers. Consequently, a war in the Middle East may have opened a new window of vulnerability in the Taiwan Strait where the US faces a more formidable adversary.

Western military powers have been treating technological overmatch as a substitute for numerical strength by assuming that future wars would be quick and precise. Iran’s asymmetric strategy has taken advantage of this illusion by making the war unsustainably expensive rather than defeating Israeli or American airpower. The repeated interception of USD 50,000 drones with USD 2 billion interceptors does not constitute a tactical victory but a strategic failure through exhaustion. Although the US-Israel war against Iran offered a glimpse of this reality, a war over Taiwan, against a substantially larger adversary, would strain the western magazine depth within just days.

This aspect yields important lessons from two pertinent concepts: first, magazine depth, which is the number of missiles and interceptors a state can maintain in the fight; and second, magazine breadth, which is its ability to use a diverse mix of capabilities against different threats at varying costs. Reliance on a handful of expensive and high-end interceptors is dangerous, as sustenance and adaptability are becoming crucial in the modern era.

The future deterrence will thus be based on a combination of magazine depth and breadth. Consequently, advanced interceptors and lower-cost kinetic systems, AI-based battle management, the use of electronic warfare, directed-energy weapons, and other layered defences that are able to withstand the saturation attacks, will define the future of warfare. For the US emergency procurement of interceptors is already underway with both RTX and Lockheed Martin, but this is not likely to provide a viable solution. The more significant requirement is the cost-exchange ratio with the new generation of defence technologies, left-of-launch networks that neutralise missiles before they hit the launch pad, and allied industrial ecosystems that would be able to rapidly replenish stockpiles during war.

In an era of contested aerospace dominance, the most advanced weapons do not guarantee air superiority and strategic success, rather it is the deepest magazines, the broadest defensive toolkit, and the industrial capacity to regenerate combat power under fire that determines the outcome.

The views expressed in this article belong to the author and do not necessarily reflect the editorial policy of Middle East Monitor.