US Dangerously Downgrades Microwave Weapon Program

In February 2024, Asia Times noted the differences between lasers and HPM weapons regarding function, physical characteristics and lethality. By blinding optical sensors or cutting through control surfaces, lasers can damage physical components.

On the other hand, HPM weapons can deliver energy that can overwhelm critical components carrying electric currents such as circuit boards. Additionally, HPM weapons can penetrate solid objects and engage targets over a large area.

Lasers are usually measured in kilowatts and emit infrared and visible light whereas HPMs are measured in gigahertz and have wavelengths 10,000 times longer than lasers.

Lasers perform differently depending on the environment. In contrast, HPM weapons tests have yielded more consistent outcomes. Whether the findings of small-scale HPM weapons tests can be reproduced in real-world settings at higher power levels is yet to be determined.

The lethality of laser weapons is determined by the time the laser is concentrated on the target, which affects the amount of energy delivered. Conversely, the effectiveness of HPM weapons is determined by the frequency used, the rate of microwave pulses and the maximum power output.

HPM weapons have limitations that hinder their effectiveness. They suffer from high energy losses in the air, and their range is often limited in atmospheric ground-based systems. Additionally, their large size and substantial power consumption limit their deployment on smaller platforms.

Operation Prosperity Guardian, the US combined operation against Houthi rebels in the Red Sea, has highlighted the need for cost-effective weapons systems that promise negligible cost-per-shot against low-end targets such as suicide drones and less-sophisticated anti-ship missiles.

In January 2024, Asia Times noted that Operation Prosperity Guardian saw the US and its allies use multimillion-dollar missiles, such as the SM-3 Block IIA, against Houthi drones costing just $2,000, raising sustainability and cost-effectiveness concerns.

Apart from cost, the ongoing conflict also highlighted magazine depth concerns and limited missile stocks. While the Ticonderoga-class cruisers have 122 vertical launch missile cells, and the Arleigh Burke-class destroyers have 96, missiles such as the SM-3 Block IIA may have an extended lead time for replacement due to their complexity, which may strain stockpiles.

Moreover, stockpiling is not a sustainable option for filling missile inventories as missiles require specialized storage facilities, periodic checks, maintenance and upgrades, which drives up lifetime costs. Stockpiling also incentivizes storing the bare minimum of missiles to keep costs down.

Gun-based systems, such as the 20mm Phalanx Close-In Weapons System (CIWS), have a low shootdown rate of 60-70% . While it can hit drone and missile targets closer than one nautical mile, the closer the threat gets to the warship, the greater the chances of a successful attack.

While the US and its allies struggle to find a solution against the low-cost drone and missile threat in the Red Sea, those challenges may become even more pronounced in the Indo-Pacific theater.

USNI News mentioned last month that on top of those issues encountered in Operation Prosperity Guardian, the Indo-Pacific theater poses additional challenges, such as vast distances involved and more sophisticated threats.

USNI News notes that US joint forces suffer from a lack of redundant, resilient, soft/hard kill options against anti-ship ballistic missiles (ASBM) fielded by China's People's Liberation Army-Rocket Force (PLA-RF), particularly the DF-21D“carrier killer” ASBM.

Sign up for one of our free newsletters

• The Daily ReportStart your day right with Asia Times' top stories
• AT Weekly ReportA weekly roundup of Asia Times' most-read stories

Aside from ASBMs, China's hypersonic weapons also pose a significant threat to US and allied forces in the Pacific. In February 2023, Asia Times reported on China's YJ-21 hypersonic anti-ship missile, which is reportedly capable of traveling up to Mach 10.

China claims no shipboard defense system can intercept a missile at that speed, and even without an explosion, the sheer impact force will have devastating effects on the target. The YJ-21 is likely reserved as a strategic weapon against US carriers, the centerpieces of US force projection in the Pacific.

Despite the threat sophisticated ASBMs and hypersonic missiles pose to US and allied forces in the Pacific, the US may have moved too slowly in developing HPM countermeasures.

In a May 2021 Proceedings article , James Winnefield points out that the US's lack of urgency in developing HPM weapons for shipboard defense may stem from having never experienced a sophisticated anti-ship or hypersonic missile attack against its warships.

He mentions HPM weapons' lack of a visible firing signature alongside unfounded concerns such as adequately shielded HPMs harming adjacent systems or people or that properly targeted HPM weapons can cause collateral damage as mental barriers hindering their accelerated development.

He also says that force designers' lack of understanding of new technologies, alongside deliberate delays and piecemeal work by developers to keep funding coming, are in part responsible for the lack of HPM weapon traction in the US Navy.