Last month, just in time for Christmas, Germany got an unwelcome present. Namely, its biggest spy scandal in decades, with the arrest of a suspected Russian mole embedded deep inside Berlin’s intelligence system.

The suspect, identified in Germany only as Carsten L. due to stringent privacy laws (his surname is Linke), is a 52-year-old married father and colonel in the German military who, since 2010, was assigned to the Federal Intelligence Service, or BND.