It wasn’t too long ago (the 90s?) when all foreigners were thought to be spies and needed minders to travel outside of big cities. It is obviously much better now, but not all of that sentiment has washed out (see recent Beijing subway posters encouraging girls not to spill state secrets to foreign boyfriends).
I’m not really sure when someone would say bias has crossed over into xenophobia, they are not very distinguishable anyways.
Not parent but I think secrets in this case are similar to the divide of information between FTEs and Contractors in many companies. In addition, this is more of an exercise in cementing patriotic duty in the minds of citizens rather than actually preventing classified information leakage.
