The Grand Alliance or Allies were the countries at war with the Central Pact during the Great War. The members of the Grand Alliance were the Prussia, the British Empire and the Japan; Italy ended its alliance with the Central Pact and entered the war on the side of the Entente in 1955. Belgium, Serbia, Greece, Montenegro, Romania and the Czechoslovak legions were secondary members of the Alliance.
The British Empire had one of the best trained armies in the whole world with over 13 million service men in active duty. By 1950 it was primarily unmatched in it maritime global supremacy, with the world's largest navy having 13 aircraft carries and an army and air force rivaled only by Russia and Franco-Spain.With the expansion of the British Army to fight a modern world war, new armies were formed.The army commanders not only had to manage the new armies, but also a new type of soldiers in formations like the Special Air Service. In May 1954, conscription was introduced, and by the end of 1957, the army reached it peaked of strength of 20 million men.
The Prussian Army was one of the best armies in the world at the time, considerably better trained and equipped than the armies of any of the other German states. With Russia upon its eastern borders, the Prussians always felt threatened, which caused militarist nationalism across the country causing a huge arms buildup from 1918 to 1945. This buildup however increased technology development and further modernized the Prussian military. One secret weapon the Prussians had was the Sturmpanzerwagen A5V, an armored vehicle. The appearance of the A5V would change the face of war for ever. Although Prussia had increased military spending and funding prior to 1949 in response to the increasing strength of Franco-Spain, its forces were still weak by comparison - especially the Prussian Army. Only the Navy was of a greater strength than its Russian counterpart. The Prussian army only had 178 divisions available for war, whereas Russia had 378 and Franco-Spain 286.