In case you're interested what a dark sky town ordinance looks like for a small town that has the designation near where I live, see here[1].
[0] https://www.darksky.org/our-work/conservation/idsp/finder/ [1] https://codelibrary.amlegal.com/codes/torreyut/latest/torrey...
https://www.darksky.org/our-work/conservation/idsp/communiti...
I can think of a lot of towns outside the US that have excellent dark skies but they aren't listed here.
[0] https://www.darksky.org/our-work/conservation/idsp/parks/
[1] https://www.darksky.org/our-work/conservation/idsp/reserves/
[2] https://www.darksky.org/our-work/conservation/idsp/sanctuari...
I can think of several dozen places and parks in northern Scandinavia, western China, Mongolia, Canada that are almost devoid of light pollution that aren't even on this list.
Also almost the entire country of Iceland and all of its parks are excellent dark sky and not even mentioned here.
And that's just places I have personally been. I'm sure there are huge parts of Africa, Australia and the Middle East, and South America are excellent as well, and one would think that if I were to travel to those continents that I could look to a website called the "International" Dark Sky Association to find out where the best dark sky parks are in those places. But no.
It just seems a bit hypocritical to me to call it "International" but with very little attention to the wealth of excellent dark sky areas outside the US.
I'd say it's mostly because there is an application process. Unlike for example travel guides where people go around the world to discover new places, IDA is waiting for those places to apply. If you add the language barrier, the quite long list of requirements and political actions to make to be able to apply, that only reduces the list of candidates.
I suppose there are also less-known local initiatives throughout the world. Here in France, we have the ANPCEN [0], fighting against light pollution and delivering labels to cities that take actions against light pollution (like shutting off the streetlights from 11PM to 5AM).
[0] https://www.anpcen.fr/?id_rub=19&rub=participez-%E0-villes-e... (in French, but there is a Google Translate button in the footer)