@freemo plus ça change plus c’est la même chose 😉. Less flippantly and as you point out it is somewhat more complex. The Convention is part of the packages associated with sign up to various UN and other international institutions, but ultimately the only ‘police’ are the citizens of individual countries, so a most imperfect arrangement. Of course there are border checks the key being whether people are treated as such or not. Our principles are admirable our practice Is often wanting!