A System at Risk: America's Strategic Vulnerability in GPS (Part 1 of 3)

Members of the Defense Contract Management Agency prepare to load the GPS III Space Vehicle 10 aboard a C-17 Globemaster III on January 6, 2026, at Buckley Space Force Base, Colorado. GPS III satellites bring advanced mission payloads, increased signal power, enhanced anti-jam capability, and improved accuracy, ensuring the GPS enterprise remains the global benchmark for precision navigation and timing.

(U.S. Space Force photo by Staff Sgt. Amanda Flower)

Abstract

The U..S.. Army’s longstanding reliance on Global Positioning System (GPS) has created a strategic vulnerability as near-peer adversaries develop kinetic and nonkinetic counter-space capabilities capable of degrading or destroying satellite-based Positioning, Navigation, and Timing (PNT). Emerging jamming, spoofing, and space-denial threats require the Army to field resilient alternatives capable of operating in degraded, denied, intermittent, or limited (DDIL) GPS environments. This paper examines the technological pathways—AI-enabled inertial correction, Simultaneous Location and Mapping (SLAM)-based navigation, multispectral terrain association, and distributed sensor meshes—that can restore freedom of maneuver and support precision targeting when GPS is contested. It also outlines the operational risks of these systems, including electromagnetic signature exposure, terrain limitations, and adversary deception. Given its doctrinal responsibility for assured mobility and geospatial engineering, the Engineer Regiment is positioned to lead requirement development and integration of these capabilities in coordination with the Army AI Integration Center, enabling the Army to guide Research Development Test and Evaluation (RDT&E) investment and transition viable PNT solutions into Programs of Record.

A Brief History of the Military Applications of GPS

U.S. Space Force Guardians assigned to Space Delta 5 conduct military planning Dec. 18, 2025, at Vandenberg Space Force Base, Calif. Space Delta 5 supports and presents combat-ready forces to command and control the Combined Space Operations Center, which closes blue kill chains by delivering space-enabled effects—including GPS, missile warning and electromagnetic interference detection—to the Joint Force.

To deter conflict, planners often work to understand what an initial act of aggression by an adversary might be and devise ways to either raise the cost of aggression or degrade the value of success. For China, counter-space operations are viewed as a likely element of any offensive opening salvo,[1] and it is therefore in our national interests to take deliberate actions to alter the risk calculus of counter-space through better defending the target, decreasing the benefit of a successful attack, or both.

The role of GPS in military operations has been clear since the tanks and trucks of VII Corps crossed the Arabian Desert into Iraq in 1991. The satellite constellation that makes the system possible was ultimately labeled critical U.S. infrastructure in 2021,[2] after years of debate that can be traced to at least 2015.[3] Today, military reliance on GPS is widespread, enabling positioning, navigation, and timing (PNT) for personnel, vehicles, vessels, aircraft, and munitions, including the High Mobility Artillery Rocket System (HIMARS)-launched Guided Multiple Launch Rocket (GMLR), Howitzer-fired Excalibur rounds, and aerially delivered Joint Direct Attack Munition (JDAMs) used so effectively in contested regions of Ukraine.[4],[5],[6] The precision provided by the munitions facilitates the hyper-focused targeting model that limits civilian casualties on the modern battlefield—a cornerstone of how the American public expects our military to conduct conflicts in the modern era and a key enabler of the trust that exists between the public and the military.[7],[8],[9] The fact that the constellation not only enables our military capabilities but also underpins aspects of our national industrial base supports our commercial delivery model. It also enables the military to conduct a conflict in line with our national values, making the constellation a rich target, especially for an adversary that integrates a whole-of-state approach to the competition continuum.

We have not always relied on GPS to this extent: the Tomahawk cruise missiles used to such devastating effect in the First Gulf War were directed by a terrain contour matching guidance system rather than by GPS,[10] while our current fleet of submarines relies on a combination of technologies, including inertial navigation. Alternatives exist, including long-range navigation (LORAN) and enhanced long-range navigation (eLORAN), for navigation and position data; but, due to a variety of factors, including plummeting costs of GPS and lack of a consistent government sponsor, these alternatives have low adoption rates. There are obvious exceptions to our reliance on GPS, but few would disagree that the system underpins and enables many of the key technologies the U.S. military uses to wage war today.

The Engineer Regiment—responsible for mobility, counter-mobility, survivability, and maintaining Standard and Shareable Geospatial Foundation (SSGF)[11]—will play a central role in developing and fielding the next generation of DDIL navigation systems. Fortunately, the technologies required for this transition already exist across the Army, joint, and academic communities; the challenge lies in integrating them into resilient, scalable, and tactically viable solutions for ground forces.

A System at Risk

U.S. Army Pfc. Samuel Ford, with 1st Platoon, Bravo Company, 2nd Battalion, 10th Mountain Division, uses a GPS camera to document a culvert during a patrol in Wardak province, Afghanistan, on Dec. 21, 2010.

(DoD photo by Sgt. Sean P. Casey, U.S. Army. (Released))

Unfortunately, as GPS technology has matured, our reliance on it has also increased. To their credit, Congress took notice when it passed the Frank LoBiondo Coast Guard Authorization Act of 2018 but has yet to appropriate the funds for a new system, and development has not occurred.[12]

China, our pacing threat,[13] has already established the capability to destroy a satellite.[14] Combined with the destructive capacity, the denial impact of residual debris from both the target and munition on the orbits used by GPS satellites would enable China to force the U.S. military to adapt to a DDIL GPS operating environment, potentially indefinitely. Even if the constellation itself is undamaged, improvements in jamming and spoofing can degrade GPS locally. In cases where denied environments do exist, such as Ukraine, efforts at developing alternative targeting technologies have been regressive—including reverting to tethered drones,[15] at least until orbits can be established at alternate elevations or the debris can be removed.[16],[17]

The resulting impact is the same: the United States would be forced not only to revert to alternative navigational methods—now highly atrophied—but also to fight a war with limited ability to employ highly discriminatory munitions, creating operational friction between the forces in contact and the civilian support base.

There are incentives for continued GPS integration: receivers are cheap and abundant and the constellation is reliable. Government policy reinforces those incentives: DoDD 4650.05 codifies the Department’s responsibility to provide and protect space-based PNT and to govern the DoW PNT enterprise—effectively embedding GPS into the acquisition, oversight, and resourcing processes. Space Policy Directive 7 reinforces that national mandate by directing implementation actions for U.S. space-based PNT programs. Without an impetus for change, adoption of a new system will be slow or stalled.[18]

In an age when the military is charged with rapidly adopting AI,[19] we need to use it not just as a tool for automation, but also as a means of changing how we accomplish even the most fundamental tasks.

How We Know Where We Are

U.S. Marine Corps Cpl. Ryan Vaughn, a field artillery sensor support Marine with Fox Battery, sets up two AN/PSN-13 Defense Advance GPS Receivers to coordinate fires with a High Mobility Rocket Artillery System during exercise Baltic Operations 2025 (BALTOPS 25), June 4, 2025. BALTOPS 25, provides a unique training opportunity to strengthen combined response capabilities critical to preserving freedom of navigation and security in the Baltic Sea.

(U.S. Marine Corps photo by Lance Cpl. Van Hoang)

Fortunately, the military already possesses the underlying equipment and datasets necessary to begin rapid development of alternative navigational technologies, especially for ground-based forces. It is first important to clarify key terms and definitions: there are three primary means of navigation—celestial, terrain association, and path integration. Celestial includes any means of navigating via space-based points of reference and includes everything from sextants to GPS. Terrain association involves using a compass to plot an azimuth to a known point. Path integration is a little more complex: it uses your body’s natural understanding of its position in space, combined with your movements, to figure out where you are in relation to your surroundings.[20]

Anyone who has ever walked to the bathroom in the dark has used path integration. It’s intuitive, but difficult to quantify. That is slowly changing with advances in medicine: the 2014 Nobel Prize in Physiology or Medicine was awarded to a pair of researchers "for their discoveries of cells that constitute a positioning system in the brain.”[21] Data scientists are applying the lessons learned from this research to vastly improve navigational and positional accuracy algorithms.[22]