More than a million migrants have arrived in Germany, but the government emphasizes that far fewer will stay. So far, only 660,000 have permission to remain, officials said. And the federal government has urged Germany’s 16 states to double last year’s total of almost 60,000 deportations.

To whittle down the numbers, the authorities are halting family reunifications for two years and rejecting tens of thousands of applicants from the Balkans, Algeria and Morocco, arguing that these countries are not at war.

The task of deciding who will stay and who will go has fallen to officials like Frank-Jürgen Weise, 64, who has led Germany’s sprawling federal employment agency, based here in Nuremberg, since 2004.

As the backlog of asylum applications surged to 300,000 last year, Mr. Weise, a colonel in the military reserves, was also tapped to lead the federal agency for migration, conveniently headquartered in this same Bavarian city.

He has called the huge backlog “an embarrassment for Germany” and said, “The impression arose that Germany has no plan as to what to do with the refugees.”