 German losses in aircraft were heavy, but the loss of trained and experienced air crews did more to undermine the strength of the Luftwaffe.On the eve on Hitler's invasion of the Soviet Union, the German bomber force had 200 fewer bombers than on 10 May 1940.In late 1940, Jeschonnek and the OKL were ordered to make preparations for assisting Benito Mussolini after the failed Italian invasion of Egypt and Italian invasion of Greece in September and October 1940.