This chapter explores the strength and the limits of the Grand Alliance, the combination that won the war, but could not secure a stable peace. The Axis proved to be only a paper alliance, whereas Britain, America and Russia did make a real attempt to concert their war efforts. The Anglo-American side of triangle was much strongest, though even there serious strains over strategy, but by summer of 1944, cooperation between all three powers was both significant and fruitful. Of these three powers, only Great Britain went to war against Germany in September 1939. The United States remained neutral, while the Nazi-Soviet Pact aligned Moscow clearly with Berlin. The focus of British diplomacy during the so-called 'Twilight War' in the winter of 1939-40 was not America or Russia, but France, with which Britain had become allied for the second time in a quarter-century.