US revives railgun tests as Iran war bleeds air defenses

Missile salvos from the Middle East to the Indo-Pacific are exposing the limits of interceptor-based defenses, and the US Navy’s renewed testing of its electromagnetic railgun suggests a possible answer.

This month, The War Zone (TWZ) reported that the US Navy has resumed live-fire testing of its prototype electromagnetic railgun (EMRG) after years of apparent dormancy, conducting a three-day test campaign at White Sands Missile Range in New Mexico in February 2025, according to a Naval Surface Warfare Center (NSWC) Port Hueneme Division review document.

The tests, carried out jointly by the NSWC White Sands Detachment and the NSWC Dahlgren Division for Naval Sea Systems Command’s Joint Hypersonics Transition Office, marked the first publicly noted activity involving the weapon since the Navy said in 2021 it would effectively shelve the program after technical hurdles stalled development.

The EMRG, which accelerates projectiles using electromagnetic force rather than chemical propellants, had previously been tested at Dahlgren, Virginia, before being moved to White Sands in 2019 for further experimentation.

Although the purpose of the latest tests remains unclear, officials suggest the system may serve as a high-speed launch platform for hypersonic research payloads as the US military expands its hypersonic test infrastructure.

The renewed activity also coincides with plans for a new class of large US surface combatants known as the “Trump class”, or BBG(X), envisioned as 35,000-ton warships armed with missiles, lasers and potentially railguns. However, the lead ship, USS Defiant, is not expected to be operational before the early 2030s.

Despite ongoing technical challenges—including high power demands, cooling requirements, and barrel wear—the US Navy still sees railguns as potentially cost-effective, long-range weapons capable of hitting targets at sea, on land, and in the air.

The BBG(X), announced in December 2025, has sparked heated debate. Christian Orr argues in a 1945 article that the BBG(X) would reintroduce naval gunfire support (NGFS) capabilities provided by the Iowa-class battleships and add new capabilities, including railguns, lasers for point defense, the Sea-Launched Cruise Missile-Nuclear (SLCM-N), 128 Mk-41 Vertical Launch System (VLS) cells and 12 Conventional Prompt Strike (CPS) hypersonic missiles, potentially making it a formidable combatant.

Conversely, Mark Cancian contends in a December 2025 article for the Center for Strategic and International Studies (CSIS) that the BBG(X) is infeasible due to design complexity, high costs, and a strategic mismatch. At an estimated 30,000–40,000 tons, he says each ship could cost up to US$13.5 billion, comparable to an aircraft carrier.

He also says that the BBG(X) program contradicts the US Navy’s shift toward distributed maritime operations, which emphasize numerous smaller, networked platforms rather than a few large, high-value targets.

He adds that, given development timelines, industrial constraints, and the likelihood of political turnover, the program would likely be canceled before completion, after consuming years and billions in development funding.

The widening US-Israel-Iran war may also be reinforcing interest in the railgun initiative.

Iran has inflicted serious damage on US missile defense systems by striking key sensors, such as the AN/FPS-132 early-warning radar in Qatar and multiple AN/TPY-2 radars linked to Terminal High Altitude Area Defense (THAAD) batteries, disrupting the region’s layered defense network, according to Turki Faisal Al-Rasheed in a Eurasia Review article.

Al-Rasheed stresses that without these sensors, remaining interceptors operate with reduced detection and targeting capability. He also points out a cost-exchange problem in which defenders must fire multimillion-dollar interceptors against cheaper missiles and drones, rapidly depleting stocks and leaving critical bases and energy infrastructure increasingly vulnerable.

Railguns could partly offset the shortcomings of missile-based defenses. A November 2021 US Congressional Research Service (CRS) report notes that the US Navy has determined that the EMRG could be used for air and missile defense, in addition to its original purpose as an anti-surface weapon. The report notes railguns provide lower-cost, high-volume interception against missile and drone saturation attacks.

To put that into perspective, Neil Hollenbeck and other writers in a February 2025 CSIS article noted that, while cost estimates of Iran’s Shahed-series one-way attack drones vary, they cost around US$35,000 per unit.

Further, Ari Cicurel points out in a July 2025 report for the Jewish Institute for National Security of America (JINSA) that Iran’s ballistic missiles, namely the Emad, Ghadr, and Khorramshahr medium-range ballistic missiles (MRBM), cost US$250,000, $5 million, and $8 million, respectively.

Contrasting the price of US workhorse interceptors, Cicurel notes that a Patriot PAC-3 interceptor costs $3 million per round. At the same time, Wes Rumbaugh states in a December 2025 CSIS article that each THAAD interceptor costs $15 million.

Further illustrating the issue, Semafor reported this month that Israel is running low on missile interceptors, per an unnamed US official who said the US expects this but isn’t similarly low on interceptors. The report notes that the US might try to supply more, but could strain its own stocks, which may already be below optimal levels.

In terms of per-shot costs, the US CRS stated that the cost of the US Gun-Launched Guided Projectile (GLGP), derived from the Hypervelocity Projectile (HVP), was estimated at $85,000 per round in 2018.

However, railguns still have their limitations. Aside from longstanding heat, weight, space, power, and barrel life problems, it is unlikely they could replace missile-based systems altogether.

As noted by Mark Gunzinger and Brian Clark in a Center for Strategic and Budgetary Assessments (CSBA) report, railguns for air and missile defense may be limited to an 18-74 kilometer range, much shorter than the range of interceptors such as THAAD and Patriot. That limitation may relegate railguns to point-defense rather than area-defense roles.

For comparison, the US CRS mentions in a September 2025 report that the THAAD can engage targets at 150-200 kilometers, while a separate CRS report from July 2025 says that while official Patriot engagement ranges are not publicly available, its radar can track targets 150 kilometers away, provide guidance for nine interceptors, can reach a maximum altitude of 20 kilometers, and provide area defense for 15 to 20 kilometers against ballistic missiles.

While the US-Israel-Iran War may have shown the limits of US missile defenses, those limits may be more starkly felt in the Pacific, especially against China and North Korea.

China has the world’s largest sub-strategic missile arsenal, capable of targeting US bases within the First Island Chain, Guam, and threatening US carriers in the Pacific.

Similarly, North Korea has continuously modernized its nuclear arsenal, diversifying its delivery platforms to include nuclear-capable underwater drones, ship-launched nuclear cruise missiles, ballistic missile submarines, and intercontinental ballistic missiles (ICBMs) capable of hitting the US mainland.

As missile arsenals expand and interception costs soar, the central challenge facing modern air defense is no longer simply stopping missiles but doing so at a scale and price that can be sustained in war.