Göring promised the encircled enemy could be destroyed by aerial bombardment. Kesselring and von Richthofen protested. They argued their commands had suffered heavy losses in two weeks of incessant fighting and the fighter and dive-bombers would be forced to operate at their maximum range. Neither man was confident of gaining air superiority. The protests were disregarded. It left the burden of preventing the Allied evacuation of Dunkirk to Kesselring's air fleet. Hampered by poor flying weather and staunch opposition from the Royal Air Force (RAF), the German operation failed.