Great Britain, Soviet Russia and the United States were thrown into alliance by German and Japanese attacks. By combining resources and coordinating military operations they could amass overwhelming forces, but immense obstacles needed to be overcome. Their deeply opposed ideologies and mentalities bred mutual distrust. Each of them needed to mobilize her entire economy and to manufacture more and better arms than the enemy, who had prepared longer and had already won immense advantages. They needed to formulate goals which did not conflict with a coordinated strategy. Although Germany and Japan benefited from unified commands and efficient internal lines of communication, each conducted her own war without joining forces, and without reaching a common understanding. The Allies, on the other hand, had to face all the problems inherent in coalitions, and their cooperation had to span vast distances. Before examining how they launched the great offensive which won them the war, it is worth looking at the programme upon which their success was founded.