ANKARA, TURKEY — Turkey expects foreign countries will withdraw support for Kurdish fighters in Syria following the toppling of Bashar al-Assad, President Recep Tayyip Erdogan said, as Ankara seeks to isolate Kurds who have long fought alongside U.S. troops. Germany’s foreign minister later said Kurdish forces should disarm and integrate into Syria’s national security structure, and Washington’s top diplomat for the Middle East said the U.S. was working on a “managed transition” for the U.S.-backed Syrian Democratic Forces, or SDF, in northern Syria. Speaking to reporters on the flight home from a summit in Egypt on Thursday, Erdogan said there