I let my then 13 yr old daughter go around Beijing by bus/subway when we lived there 10 years ago; she had a phone. Felt perfectly safe. Same thing in Tokyo. I'm not sure I would have allowed that had we been living in a big US city like LA, Chicago or NYC -- maybe it's just as safe, IDK, but the fact that anyone in the US can own/carry a weapon makes me feel much less safe than in other developed countries.