In the years immediately prior to Germany's entry into World War II, the Germans conducted many experiments and tests designed to produce satisfactory AA weapons. Even after the experiments conducted during the Spanish Civil War, and the consequent determination to commence extensive manufacture of dual-purpose AA/AT guns, the primary AA purpose of these guns was never lost sight of. The German press gave much publicity to the importance of AA guns in the defense of Germany, and the Government simultaneously proceeded to provide for the activation and equipping of AA units in unprecedented numbers. Since plans for employment of these AA units in defense presupposed close cooperation with aviation, the rapidly growing AA forces were made an organic part of the German Air Force. With the outbreak of war, the formation of new AA units for local defense as well as for field service proceeded apace.