By August 1944, the Allies had broken out of the Normandy beachhead and were rapidly exploiting a breakthrough in the German lines. In early August, Hitler ordered a heavy single pronged attack to the west to cut off the US forces to the south. Bradley recognized this as an opportunity to encircle the German Army in France. By turning Patton's Third Army, in the south, north towards Argentan, Bradley formed the lower jaw of a pincer movement while Montgomery ordered Crerar's First Canadian Army south to push towards Falaise to form the upper jaw. Connecting the Allied armies between Falaise and Argentan would completely surround the German army. To the north, Montgomery's forces struggled to push south against the German defensive line. Patton's Third Army, in concert with the XIX Tactical Air Command, was making extremely rapid progress. Late on the 12th of August, Bradley stopped Patton's forces from moving north of Argentan. The decision to stop Third Army's movement north allowed many German personnel to escape from the Falaise pocket. The failure of the Allied forces to close the Falaise Gap was the result of lack of communication directly linked to the type of personalities of the commanders.