Germany accused Russia of responsibility for a drone attack at Leipzig's airport in August and announced strong new measures against Moscow.

Even in a summer of heightened tensions between Russia and the West, the Aug. 4 incident at Germany’s Leipzig/Halle Airport stuck out.

Airport workers last month found a drone ‌laden with explosives and a detonator at the airport, an important civilian freight and NATO logistics hub in eastern Germany that is also a base for ‌several...