Closing the borders in Europe would be precisely the wrong reaction. It would not prevent migrants from coming, and would further drive them underground. It would thus entrench smuggling rings, and would lead to further restrictive measures, which would be costly and mostly useless. Such closure would exacerbate social and political tensions between States and within societies, continue to maintain chaos at borders, and would lead to validating the inflammatory anti-immigration discourse of the nationalist populist movements.
The only way forward is to accept mobility, to regulate it, to offer mobility solutions to those who need it: resettlement programmes for refugees, visas to come and look for work for the others. This means that smugglers would be mostly ousted from the mobility market and that States would reclaim an effective control of the border. Effective control of the border means that States actually know who comes into and who leaves their territory, which they don’t at present, since smugglers are the ones deciding who crosses the border, and which they won’t if they go down the closure path.