> Flexing the ability to jam GPS is pointless, since it's obvious that any state actor who has military satellites in orbit has considered this option or have the capability already.
Forget "state actors", truck drivers have taken out entire airports with GPS jammers:
* https://www.cnet.com/culture/truck-driver-has-gps-jammer-acc...
People like the Resilient Navigation and Timing Foundation have been trying for years to get some kind of GNSS backup accepted:
China has certainly put their money into resiliency (both navigation and timing):
* https://www.gpsworld.com/china-completes-national-eloran-net...
* https://rntfnd.org//2026/03/19/china-has-built-a-triad-of-sa...
* https://rntfnd.org/2023/11/28/china-eloran-used-for-critical...
Some folks are certainly cluing in: South Korea has (e)Loran and the UK and France are joining up with them:
* https://rntfnd.org/2025/04/30/the-uks-system-of-systems-appr...
* https://rntfnd.org/2025/11/12/s-korea-leads-meeting-with-u-k...
Celestial Navigation is also doable even in daylight nowadays, e.g. https://sodern.com/en/ranges/astradia
Iridium has launched its own alternative positioning and timing system now https://www.iridium.com/iridium-pnt
The US still has a fairly robust network of VOR's / VOR with DME / VORTAC stations. Good for navigation, but there's no timing component, beyond what's inherent in how they operate.
Admittedly, that'll never be of use outside aviation as its line-of-sight only. But if the sun threw a Carrington event (or worse) at us, I think a lot of western aviation could carry on.