Likelihood of Attack against the United Kingdom 7. In addition to the shortage of aviation spirit and the small and declining size of the long-range bomber force, most of which will be held in reserve for emergencies and special tasks, the following factors will also militate against the likelihood of attacks on the United Kingdom:(a) The enemy will appreciate that owing to the increasing paucity and overall inefficiency of the forces available, he could achieve no strategic results. (b) Harassing attacks can be delivered by air-launched flying bombs at a far lightercost in aircraft, air crews and aviation spirit.