The 1951 Refugee Convention is a Post-WWII international agreement that sought to deal with the humanitarian consequence of a global war. It has become a means for the 'have-nots' to economically migrate from the Third World to the perceived First World 'haves'. But the definition is relative.
Worse, the problem is not solved, just shifted geographically. Emigration is a consequence of a failure to contain and resolve internal humanitarian problems. It is easier to remove a nation's people than to solve a national social problem, but the human burden is simply relocated.
The UN is an abject failure repeated in every incident of national unrest.
The peoples of the First World have been made to feel guilt-ridden by their wealth, and so obligated to open their home country to the world's people, unconditionally.
Britain has. German has, France has. What is the consequence? Who is measuring the economic, social and environmental results? Who is the watchdog of such 1951 policy? Sixty years later, is anyone questioning its merits or evaluating it?