PARIS—Has Hungary’s Viktor Orbán won this round against the European Union? The announcement Tuesday that George Soros’s Open Society Foundations (OSF) will move its headquarters out of Budapest and set up shop in Berlin, a victim of the Orbán government’s crackdown on foreign NGOs, certainly seems to indicate as much. The question now is will the European Union push back? And how?Orbán, whose right-wing, increasingly authoritarian Fidesz party secured another term in Hungary’s national elections last month, has for years been waging an escalating war against Soros.