Complex sentence: The German Wehrmacht lacked the ability to prevent the American breakout at the western end of the Normandy beachhead in early August 1944, and the Germans were nearly enveloped at the Falaise and routed.
Split into simpler sentences: The German Wehrmacht lacked the ability to prevent the American breakout at the western end of the Normandy beachhead in early August 1944. The Germans were nearly enveloped at the Falaise and routed.