World War II allied military strategy for Europe: Churchill and Roosevelt and their advisers met in Washington in late 1941. They decided that they must fiirst make a big effort at defeating Germany, then they would tackle Japan.
The American army leaders had a tradition of massing man-power and going on the offensive, so they intended to do this as soon as they could stabilize the southwestern Pacific. They wanted to make a huge cross-channel invasion of Europe from Britain.
The Allies could not have enough ships to invade Europe before spring of 1942, so they planned to bomb Germany until then and send war materials to the Soviet armies fighting Germany in Russia.
Shipping proved to be insufficient to simultaneously supply Russia, supply British forces fighting German forces in the Middle-East, and also build up an invasion force in Britain sufficient to invade Europe by 1942, so a plan was made to invade North Africa in 1942, and this was done.
Churchill wanted to keep eating away at Germany from the Mediterranian: Africa, Sicily, Italy, and so on--a war of attrition--until Germany was weak, then invade across the Channel. American army commanders wanted to make a huge cross-channel invasion of Europe--a war of mass and concentration--as soon as possible. In 1943, the Allies approved a round-the-clock bombing campaign against Germany, but made no definite plan for a cross-channel invasion other than to agree to do it someday.
At the Tehran Conference between Roosevelt, Stalin, and Churchill, held at the end of 1943, a final blueprint for allied victory in Europe took shape. During the summer of 1944 there would be a huge-cross channel invasion of Europe and a smaller invasion of southern France, and at the same time Russia would launch an all out offensive on its front with Germany. Germany would be crushed between the jaws of a gigantic vice applied from west and east.
At first, the main Allied strategy was simply to keep England from being invaded by Germany. After that, there were several disputes between England and America about what strategy should be used.
As it happened, there were a few major points of strategy that ended up being used:
- Support the Soviet Union so as to keep many German troops pinned down in the East.
- Attack in Northern Africa and then Italy to get practice with invasions and to divert German strength.
- Stage the main attack on Germany as an invasion of France -- this is the D-Day invasion that ultimately led to the defeat of Germany.
The world War II was a very long drawn, very extensive war covering large territories in Europe as well as other continents. Further the war was very intensive involving heavy deployment of men and material. There cannot be a one static military strategy of allied forces even when considering only the European theater of war. The only common strategy that seem to have been followed fairly well during a large part of the war was to for the Allied force to combine their strength to fight Germany, and to coordinate their war efforts with each other. It must be noted that Russia did not declare war on Japan till just two days before Japan surrendered.