The concept itself was certainly not a new one, but putting it into practice under the military dogma and commander egos of the day was easier said than done. Throughout 1942 in particular, the coordination and flexibility exercised between Coningham's Western Desert Air Force (WDAF) and the 8th Army has been contrasted with the more rigid relationship between the Luftwaffe and German ground forces. During the first week of July, 1942, WDAF flew 5,458 sorties against Axis forces, using the innovative tactic of "leap-frogging" airfields, and Erwin Rommel informed Berlin on 4 July that he was abandoning his El Alamein offensive to concentrate on defence. Later, the tactic of bombing known as "Tedder's carpet" was developed.