U.S. Army Trains Pacific Soldiers on Iron Neptune for Electromagnetic Warfare in Joint Operations.

The U.S. Army is training soldiers to assemble Iron Neptune as development and procurement of the classified electromagnetic warfare system continue. The effort places electromagnetic warfare equipment directly within multidomain formations supporting joint operations.

Personnel from the 1st Multi-Domain Effects Battalion trained with Iron Neptune at Joint Base Lewis-McChord, while FY2026 budget documents provide $59.2 million for classified Iron Quest and Iron Neptune development and fund two Iron Neptune kits. The activity confirms that the system has moved beyond development documentation into unit-level training, although its technical functions and operational parameters remain classified.

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Soldiers from the 1st Multi-Domain Effects Battalion assemble the Iron Neptune electromagnetic warfare system at Joint Base Lewis-McChord on October 1, 2026.(Picture source: US DoD)

Iron Neptune is used by a specialized unit within the 1st Multi-Domain Effects Battalion, assigned to the 7th Infantry Division Multi-Domain Command-Pacific. This places the system inside a formation tasked with delivering multidomain effects in support of U.S. forces. Publicly available information does not establish the precise functions performed by Iron Neptune within this structure or the different operating modes available to the system.

According to imagery published on October 1, 2026, by the U.S. Department of War and produced by Sgt. Cody Miller of the 7th Infantry Division Multi-Domain Command-Pacific, soldiers from the Information Defense Company demonstrated Iron Neptune assembly procedures to other personnel. The official U.S. Army caption explicitly describes Iron Neptune as an “electromagnetic warfare system.” It also states that the training is intended to maintain unit proficiency in setting up tactical communications systems during joint operations. No additional details on the system’s electronic functions are provided in the publication.

The photographs nevertheless establish several concrete characteristics. Iron Neptune is shown as a ground-based system composed of multiple elements assembled by soldiers at the training site. The equipment is organized in a way that requires specific setup procedures taught to personnel. The U.S. Army does not disclose its frequency coverage, power output, range, antenna configuration, or internal electronic components. It also does not publicly specify the system’s operating modes.

U.S. Army budget documents provide additional information on the program. In the Fiscal Year 2026 Research Development Test and Evaluation request, Iron Neptune appears alongside Iron Quest under Project 907 Tactical Exploitation of National Capabilities within Program Element 0603766A Tactical Electronic Surveillance System Advanced Development. The document includes an additional $59.2 million for development of classified Iron Quest and Iron Neptune capabilities. According to the Army, the increase is intended to accelerate development of capabilities used to detect, track, analyze, and exploit different types of threats.

The $59.2 million does not represent the cost of Iron Neptune alone. It covers Iron Quest and Iron Neptune development together and includes a transfer of $24.745 million from the Air Vigilance Advanced Development effort. Funding for Project 907 rises from $50.497 million in Fiscal Year 2025 to $98.401 million in Fiscal Year 2026. Available documentation provides no public breakdown showing the portion allocated specifically to Iron Neptune.

Another Fiscal Year 2026 budget document confirms that the system is not limited to research and development activity. Under the Air Vigilance procurement line, the U.S. Army plans $3.1 million in mandatory funding to acquire one Iron Quest expeditionary kit and two Iron Neptune kits. The detailed description of these systems is explicitly listed as classified. This line is one of the few public references providing an indication of the number of Iron Neptune sets included in current U.S. acquisition planning. Fiscal Year 2027 documentation again refers to the procurement of Iron Neptune kits alongside other Air Vigilance equipment without disclosing their technical characteristics.

The available information remains limited to what the U.S. Army has made public. Soldiers from an Information Defense Company are training to assemble Iron Neptune, the service officially classifies the equipment as an electromagnetic warfare system, and budget documents show continued development alongside procurement of multiple kits. No verified public information currently supports assigning the system a specific jamming, interception, detection, or electronic protection role.

Iron Neptune’s presence within the 7th Infantry Division Multi-Domain Command-Pacific comes as the U.S. Army continues developing multidomain capabilities for the Indo-Pacific theater. Fiscal Year 2026 and 2027 budget documents show that Washington is funding both development and acquisition of Iron Neptune equipment, while the October imagery confirms its use in training by an operational unit at Joint Base Lewis-McChord. For U.S. forces and regional partners, electromagnetic warfare is therefore part of the capabilities being integrated into the Army’s multidomain formations, even though Iron Neptune’s operational parameters remain classified.

Written By Erwan Halna du Fretay - Defense Analyst, Army Recognition Group
Erwan Halna du Fretay holds a Master’s degree in International Relations and has experience studying conflicts and global arms transfers. His research interests include security and strategic studies, particularly the dynamics of the defense industry, the evolution of military technologies, and the strategic transformation of armed forces.