This scenario is so common and the list of disputed territories is so long that it should be a standard.
It could be a bit like the timezones, the locale, or the decimal point separator, or other things like that. It should be an option at the OS level that you can configure, not be forced into.
There should be a common database that you can integrate in your map, a bit like timezone historical records, and the user should be able to see the map as claimed by any given country/territory. By default this could depend on your location or locale but it should definitely be possible to always see the map as the other side of the dispute has it, and to configure your device so that it shows maps (for all map software on the device), from a given perspective.
It could be a bit like the timezones, the locale, or the decimal point separator, or other things like that. It should be an option at the OS level that you can configure, not be forced into.
There should be a common database that you can integrate in your map, a bit like timezone historical records, and the user should be able to see the map as claimed by any given country/territory. By default this could depend on your location or locale but it should definitely be possible to always see the map as the other side of the dispute has it, and to configure your device so that it shows maps (for all map software on the device), from a given perspective.