Germany began executing its carefully thought out blitzkrieg strategy on France and the Low Countries on May 10, 1940. The sudden attack shattered the nervous calm of the Phony War, and it met with immediate success. In Fall Rot (Case Red) of the campaign, German forces outflanked the Maginot Line, and within a matter of days Paris had fallen and French forces had capitulated en masse. Even though the Allies had a clear numerical advantage in artillery and tanks, the Germans were able to produce a spectacular victory thanks to superior tactics.