you couldn't flee the feudal system. your "lehnsherr" had the last word on your whereabouts. also let's go feudal, amiright: >  t_du_seigneur lol  also you could more or less easily flee the su as a soviet citizen, because the country had a huge border. just don't go to the koreas or europe and you're fine. people leaving was only a problem for korea and germany, because there was a more attractive alternative right across the border.
Germany