Earlier quoted context omitted.
I don't understand your point. My watch was not marketed to function in Afghanistan at all. It was made clear the towers are in the US(IIRC two of them), Berlin and Japan. And I think few people expect their wrist watch to synchronize over radio in a basement... And if they are, they need to understand radio better. There is little drift on my G-shock anyway. Probably it would still be extremely accurate if it hadn't…
Possibly the US military base had radio tower even though it's not their territory?
Or the German signal in light/thin buildings.
Afghanistan is far, but not _that_ far.