Navigating to Nowhere: How Non-Military GPS Puts Marines at Risk
by MSgt (ret.) David Nisbeth
In March 2025, the Marine Corps released a powerful video titled Personal Portable Electronic Device (PPED) Policy, emphasizing the critical role of signal management on the modern battlefield. The video depicts a Marine behind enemy lines who, in a moment of desperation, uses his cell phone to retrieve a GPS grid and send it via messaging to call for help, only to have his signal intercepted, his position exposed, and his rescuers ambushed. This chilling scenario underscores a stark reality: never before has a single Marine had such a direct impact on a unit’s ability to remain concealed or be revealed.
While the video focuses on personal electronic devices, it also exposes the vulnerabilities of Marines relying on commercial GPS. Originally developed as a military tool, GPS has become widely commercialized, fostering an overreliance on civilian-grade navigation systems in both military and civilian operations. Unlike secure military GPS, which is hardened against electronic warfare (EW) threats, commercial GPS signals are highly susceptible to jamming and spoofing. Adversaries can easily disrupt or manipulate these signals, resulting in disoriented troops, misguided operations, and even ambushes. As the modern battlefield becomes increasingly contested in the electromagnetic spectrum, Marines operating in the INDOPACIFIC and beyond must recognize the risks of commercial GPS dependence and be prepared to fight in GPS-denied environments.
What is PNT and Its Role in Military Operations?
Positioning, Navigation, and Timing (PNT) form the backbone of modern military operations, enabling Marines to maneuver effectively, engage targets with precision, and maintain battlefield coordination. Without secure and reliable PNT, everything from fires to logistics to communications is at risk of failure.
Positioning is essential for Marine units to locate and engage enemy targets accurately. Precision fire assets such as HIMARS and emerging ship-killing platforms like ROGUE NMESIS require exact coordinates to be effective. In contested regions like the First Island Chain, ensuring accurate PNT data is critical for long-range fires inside the enemy’s Weapon Engagement Zone (WEZ).
Navigation ensures Marine forces can maneuver across complex terrain to close with and destroy the enemy. This is especially crucial for Stand-In Forces operating within Anti-Access/Area Denial (A2AD) environments, where adversaries aim to disrupt U.S. movement and access to key terrain.
Timing is often overlooked but just as critical. Military encrypted communications, precision-guided munitions, and synchronized operations across all domains rely on precise timing. Without secure PNT, units risk losing comms, misaligned strikes, and disrupted operations, leaving them vulnerable in contested environments. Peer adversaries actively target GPS and timing signals, making resilient military-grade PNT essential for mission success.
GWOT and Signal Dominance
During the Global War on Terror, Marines operated in environments where electronic warfare threats were virtually nonexistent. In Iraq and Afghanistan, U.S. forces had near-total control of the electromagnetic spectrum, allowing Marines to rely on GPS without fear of enemy interference. This uncontested battlespace created a false sense of security, leading to an overreliance on GPS-based navigation and a decline in traditional land navigation skills.
In 2004, the Department of Defense introduced the Defense Advanced GPS Receiver (DAGR) as the standard military GPS handheld. However, in both theatres of operation, these devices were limited in number and primarily mounted in vehicles, often integrated with Blue Force Tracker for force tracking and navigation. On foot, Marines found the DAGR to be clunky, difficult to operate, and impractical for fast-paced combat scenarios. As a result, many turned to commercial GPS devices like Garmin handhelds and TomTom units, which were more user-friendly and readily available. It became common to see squad leaders patrolling the streets of Fallujah or the rugged terrain of Helmand with a Garmin strapped to their gear, relying on it as their primary navigation tool.
Despite providing quick access to coordinates, commercial GPS devices were effective when U.S. forces dominated the electromagnetic spectrum. However, in today’s fight against peer adversaries with advanced EW capabilities, this mindset is fatal. These devices lack encryption, anti-jamming protections, and spoofing resistance, critical safeguards in contested environments, leaving Marines highly vulnerable on the battlefield.
Facing Peer Adversaries with Advanced Jamming and Spoofing
Unlike the uncontested battlefields of Iraq and Afghanistan, today’s operational environment is defined by EW threats from peer adversaries such as China and Russia. These nations have invested heavily in GPS jamming and spoofing technology, recognizing that disrupting an opponent’s ability to navigate and communicate can be just as effective as kinetic strikes.
Russia has demonstrated its electronic warfare capabilities in Ukraine, where its military has repeatedly employed GPS jamming to disrupt Ukrainian drones, artillery systems, and command-and-control networks.
China, meanwhile, has taken EW a step further, integrating it deeply into its People’s Liberation Army (PLA) doctrine. In the INDOPACIFIC, China has actively spoofed GPS signals in the South China Sea, causing false position readings for the Maritime shipping industry and military vessels.
For Marines operating inside the WEZ of a peer adversary, the assumption that GPS will always be available, accurate, or reliable is dangerously flawed. To maintain battlefield dominance, the Marine Corps must transition to hardened military PNT solutions and rebuild warfighter proficiency in GPS-denied navigation techniques.
M-Code and Its Benefits for Marines
As the battlefield becomes increasingly contested and adversaries like China and Russia enhance their electronic warfare capabilities, the U.S. military is transitioning to Military-Code (M-Code) GPS, a system designed to provide a more secure and resilient PNT.
Civilian GPS operates using the Coarse Acquisition (C/A) code, an unencrypted signal broadcast on the L1 frequency (1575.42 MHz). While C/A provides basic navigation for civilian users, it is highly vulnerable to jamming and spoofing due to its open-access nature, making it unreliable in a contested environment.
Military GPS traditionally relies on the P(Y) code, an encrypted signal transmitted on both the L1 and L2 frequencies (1227.6 MHz). The use of dual frequencies improves accuracy and offers some resistance to interference, but P(Y) is still susceptible to advanced electronic warfare threats.
To counter these vulnerabilities, the U.S. military has developed M-Code, a next-generation military GPS signal with enhanced encryption, anti-jamming, and spoofing resistance. Unlike C/A or P(Y), M-Code provides a stronger, more resilient signal, ensuring reliable PNT in GPS-contested or denied environments.
M-Code operates on both the L1 and L2 frequencies, leveraging dual-frequency capability to further strengthen its resistance to electronic warfare threats. By receiving signals from both frequencies, M-Code-enabled receivers can filter out interference, mitigate spoofing attempts, and improve accuracy in degraded environments. This advanced capability makes M-Code a critical enabler of modern military operations, ensuring warfighters can shoot, move, and communicate with the precision and reliability necessary to maintain a tactical advantage on the battlefield.
M-Code is built to resist deliberate jamming and spoofing by adversaries, offering greater resilience against electronic warfare threats. The new signal is more secure, ensuring that only authorized users can access the precise positioning information it provides. This encryption makes it nearly impossible for adversaries to manipulate or disrupt the signal, a critical advantage in a high-tech, contested operational environment. Moreover, M-Code incorporates advanced anti-jamming technologies, allowing it to function in situations where traditional GPS signals would fail. This capability ensures that Marines will still be able to navigate, call in fires, or conduct operations even in the face of aggressive enemy EW actions.
For the Marine Corps, the integration of M-Code receivers into operations is not just a technological upgrade, it’s a necessity for ensuring operational superiority in modern warfare. The Marine Corps must transition to M-Code-enabled systems across all platforms, from individual handheld devices to combat vehicles and aircraft, to ensure that Marines can operate securely and effectively on future battlefields. This shift will allow Marines to maintain situational awareness, navigate with precision, and execute coordinated, complex operations without the risk of enemy interference. By embracing M-Code, the Marine Corps will not only increase the security of its GPS systems but also strengthen its ability to fight and win in a GPS-contested world.
Digital Natives
Today’s Marines have grown up in a digital world where smartphones, GPS apps, and navigation tools are second nature. While these technologies provide instant access to directions and locations, they have also led to a decline in traditional navigation skills like map reading, compass use, and terrain association. This overreliance on GPS has not only reduced confidence in manual navigation but also fostered a lack of understanding of how GPS works, and how vulnerable it can be to enemy disruption.
One of the most significant tools in modern Marine Corps operations is the Android Tactical Assault Kit (ATAK), a system that integrates GPS positioning, communication tools, and map overlays to enhance real-time situational awareness. ATAK provides Marines with a common operational picture, improving coordination and decision-making in dynamic environments. However, ATAK often relies on commercial GPS receivers, making it susceptible to jamming and spoofing.
The Fatal Flaw of Commercial GPS Dependence
Despite the Marine Corps’ emphasis on preparing for GPS-contested operations, many units unknowingly jeopardize mission success by relying on commercial GPS. Whether conducting heliborne raids, reconnaissance insertions, or routine navigation, Marines often default to ATAK without recognizing its vulnerabilities. While ATAK enhances real-time situational awareness, it is only as reliable as the GPS signals it receives, making it a prime target for enemy disruption.
A clear example is seen in pre-deployment workups like the MEU, where companies undergo hyper-realistic training in unfamiliar terrain. During heliborne raids, platoons frequently use ATAK to track movement and navigate to the objective area, assuming it will function as reliably in combat as it does in training. However, ATAK’s dependence on commercial GPS is a critical weakness, one that could prove disastrous against a peer adversary with advanced electronic warfare (EW) capabilities.
In an actual fight, enemy forces could jam, spoof, or corrupt GPS signals, leaving Marines disoriented, misrouted, or even lured into an ambush. Without a hardened military PNT solution and proficiency in GPS-denied navigation, Marines risk losing the ability to maneuver, coordinate, and execute missions with precision when it matters most.
A similar issue arises in Reconnaissance teams conducting military freefall operations. ATAK provides jumpers with real-time wind data, helping them adjust their flight path for optimal drop zone accuracy. However, commercial GPS struggles to acquire a reliable signal inside an aircraft, causing some jumpers to exit on a false heading. It often takes critical seconds or even minutes before their GPS re-acquires a correct position, forcing them to adjust mid-flight. In combat, enemy forces can exploit this vulnerability, spoofing signals to mislead specialized teams, leading to mission failure or worse.
With peer threats actively developing EW capabilities, unit leaders must educate their Marines on the differences between civilian and military GPS. It is essential that small unit leaders establish SOPs for GPS-denied operations and enforce proficiency in map reading, terrain association, and compass navigation. Marines must be prepared to fight with or without GPS, ensuring they can operate even when their digital tools are compromised
Adapting to the Fight Today
The future of military operations hinges on the Marine Corps' ability to seamlessly integrate new technologies like M-Code with foundational navigation skills such as map reading and compass use. As adversaries continue to evolve their EW capabilities, ensuring the resilience of our PNT systems becomes critical to maintaining operational superiority. M-Code offers a robust solution by providing secure, jam-resistant GPS signals, but it must be complemented with traditional navigation skills. This combination of cutting-edge technology and core skills ensures that Marines can operate effectively in GPS-denied environments, preserving their tactical dominance.
By embracing both advanced PNT technologies and traditional navigation techniques, Marines will not only preserve their lethal edge but also enhance their survivability in high-conflict scenarios. Adaptability in leveraging these tools will be paramount, allowing Marines to maintain battlefield awareness, execute precise maneuvers, and remain unpredictable in the face of evolving threats. Ultimately, this integrated approach will safeguard the Marine Corps' position as the most formidable and lethal fighting force, capable of overcoming any challenge and maintaining tactical dominance in the most contested environments.
MSgt Dave Nisbeth is a retired Recon Marine with over 20 years of operational experience in the U.S. Marine Corps. His career included combat operations in OIF & OEF, counter piracy and maritime interception operations, crisis response, and missions in support of U.S. SOCOM. He is now a consultant for Technology Advancement Group, serving as a subject matter expert on military navigation.
Thanks for the article, raises some good points about potential near-peer conflict.