Many European countries also had rules that civilians were not allowed to possess military calibers - which would be 9mm.
Not sure if police would be covered, or not.
Mexico has a similar law which accounts for the popularity of 1911’s in .38 Super in the Southwest.
European police are exempted or are sometimes even part of the national military, so no, a civilian ban on 9mm would not affect them.
Local cops in Nice had .357 revolvers with cavalry lanyard rings and lanyards about half a dozen years ago. Surprised me.