Jean-Claude Juncker is the famously bibulous president of the European Commission. In the following video he touts the admission of Romania to the Schengen Zone — the European countries bound by treaty to accept mutually visa-free travel. He describes the process as inevitable. Romania will join Schengen; it is a given.
Think about why Mr. Juncker and the EC are doing this: there is no direct land connection between Romania and the rest of Schengen, except through Hungary. The migrants sometimes land directly in Romania, after crossing the Black Sea from Turkey. Presumably the pace will accelerate once Romania is a Schengen country.
With Romania in the Schengen Zone, Hungary will be unable BY LAW to deny entry to anyone who wants to cross the border from a fellow Schengen state. The fence will be irrelevant.
In this manner the EU will be backing Hungarian Prime Minister Viktor Orbán into a corner. If Orbán refuses to obey, the European Commission can haul him before the European Court of Justice, which will probably rule against him. At that point, he will either have to cave, or Hungary will have to leave the EU.
So that’s the game that’s afoot. It will be interesting to see how this all plays out.