Germans can have little hope that new measures in that U-boat warfare such as re-armament, technical re-equipment or new tactics, or indeed any action at sea by them, will have a decisive effect on the strategy of the war as a whole during the next six months. 5. Allied Air Offensive. Finally, and of ever increasing importance, the Allied air offensive which has developed against Germany during the last four months is causing the German Command the greatest anxiety. Although the areas as yet affected form only a comparatively small part of German territory, they include some of the primary industrial and most densely populated regions.