Hungary’s right-wing Prime Minister Viktor Orban thinks he knows the best place — on Macedonia’s and Bulgaria’s borders with Greece — smack along the main immigration route from the Middle East to Western Europe. The plan is especially controversial because it effectively means eliminating Greece from the Schengen zone, Europe’s 26-nation passport-free travel region that is considered one of the European Union’s most cherished achievements. The Visegrad group is also becoming a force that threatens the plans of German Chancellor Angela Merkel, who wants to resettle newcomers across the continent while also slowing down the influx. “The plan to build a new ‘European defense line’ along the border of Bulgaria and Macedonia with Greece is a major foreign policy initiative for the Visegrad Four and an attempt to re-establish itself as a notable political force within the EU,” said Vit Dostal, an analyst with the Association for International Affairs, a Prague-based think tank. The leaders will try to hash out a unified position ahead of an important EU meeting Thursday and Friday in Brussels that will take up both migration and Britain’s efforts to renegotiate a looser union with the EU.