Post low-effort but interesting theories.
What if there is like a World Government (not necessarily evil like in One Piece)? After all, there was once a war but now everyone seems peaceful, with the main threat to world peace being paramilitary terrorist/yakuza organizations like Team Rocket and evil megacorporations. Most importantly, there is an "International Police" which seems to have authority over the local policewomen and men. Finally, the world dex is called the 'national dex'. Obviously the word 'international police' implies some 'national' autonomy, but how much is there?