Satellite navigation can no longer be treated as a given on any movement through contested airspace, and this week's Gulf picture makes the point. The FAA's updated GNSS Interference Resource Guide, revised to version 1.1 in March 2026, lists the worst-affected areas as the Eastern Mediterranean, the Black Sea, Russia and the Baltic, the India-Pakistan border, Iraq and Iran, the Koreas, and around Beijing.
The scale is not marginal. Open-source reporting cites more than 430,000 recorded GNSS jamming and spoofing incidents in 2024, affecting somewhere between 700 and 1,350 flights a day, with IATA logging a 67 per cent rise in 2025 and a 193 per cent increase against 2023. More than 700 flights in Gulf corridors had recorded suspected spoofing by March 2026, and over 1,100 vessels reported GPS interference in the Strait of Hormuz inside a single 24-hour window.
The distinction matters. Jamming drops the signal, which is obvious. Spoofing is worse, because it feeds a plausible but false position, and a crew or a driver can be confidently, precisely wrong. Layer Tehran's partial-then-full airspace closure for the funeral over that, and route planning near Iran this week has to assume degraded and deceptive navigation as the baseline.
The mitigations are old-school and they hold. Cross-check position against inertial navigation, fall back to ground-based aids like VOR and DME, use air-traffic control for verification, and run multi-constellation receivers so a single spoofed system does not carry the plot. On the ground it means pre-planned routes that do not depend on live satnav, offline mapping held on the vehicle, and briefed crews who know what a spoof looks like before it happens.
Operator implication: build GNSS denial into the movement plan by default, not as an exception. Brief it, carry the backups, and rehearse the revert to manual navigation. In the Gulf this week it is not a contingency, it is the operating environment.
