What is the difference between the Europe first policy and the ABC-1 talks?

Question:

from what I understand they are both about focusing the war on Germany first and then moving to Japan. Can you please tell me what the differences are?

Answer:

Europe first, also known as Germany first, was the key element of the grand strategy employed by the United States and the United Kingdom during World War II. According to this policy, the United States and the United Kingdom would use the preponderance of their resources to subdue Nazi Germany in Europe first. They would also fight a holding action against Japan in the Pacific, using fewer resources. After the defeat of Germany—considered the greatest threat to Great Britain—all Allied forces could be concentrated against Japan.

Before the United States entered the war, American and British officials met from January to March 1941 for the ABC-1 talks and agreed on a strategy for defeating the Axis nations. They decided that because Germany represented the stronger enemy, British forces in the Mediterranean would hold their positions. In the Pacific, American forces would go on the strategic defensive, while Allied armies in Europe built up for an eventual landing on the continent followed by a victorious march to Berlin.

Soon after the declaration of war, the United States and the United Kingdom agreed at the Arcadia Conference on the "Europe first" strategy, and the United States committed to sending its army and air force to fight Germany in Europe and Africa as soon as those forces were ready. The campaign against Japan would be focused on halting Japanese expansion until the war on Germany was complete, at which time the full power of the United Kingdom, the United States, and eventually the Soviet Union could be turned against Japan. This strategy would concentrate on what was perceived as the strongest of the Axis Powers, and would prevent a German victory that might knock the United Kingdom or the Soviets out of the war.

After December 1941, however, events worked to modify this strategy. First, the U.S. Navy successfully bid for higher priority in the Pacific in an early two-pronged assault on Japan, one from Australia and New Guinea through the Philippines, the other through the islands of the South and Central Pacific. Second, in Europe, British demands for action in the Mediterranean and the immediate need for a reduction of German pressure on the Soviet Union diverted British and American forces to fight in North Africa. These developments left only the England-based Allied air forces to attack the German homeland through a strategic bombing campaign.

The "Europe First" strategy did not go along well with factions of the US military, driving a wedge between the Navy and the Army. While USN Fleet Admiral Ernest King was a strong believer in "Europe First", contrary to British perceptions, his natural aggression did not permit him to leave resources idle in the Atlantic that could be utilized in the Pacific, especially when "it was doubtful when — if ever — the British would consent to a cross-Channel operation". King once complained that the Pacific deserved 30% of Allied resources but was getting only 15%. In spite of (or perhaps partly because of) the fact that the two men did not get along, the combined influence of King and General Douglas MacArthur increased the allocation of resources to the Pacific War.

One clear result of the Europe first policy was that battles in the European theater tended to be set-piece, pre-planned events. With fewer resources, the United States commanders in the Pacific tended to run much smaller, innovative operations and were forced to be more flexible in their strategic planning, in order to save lives. For example, as a result of fortuitous events, the Battle of Leyte and later Battle of Iwo Jima were undertaken with almost no strategic foreplanning.

The differences in the theaters were also due to their nature; as Europe was heavily land-based, the best perceived way to beat Nazi Germany was to invade the continent. When Germany surrendered, Berlin had been captured and only Norway and Denmark remained in Axis hands. By contrast, to defeat Imperial Japan, a naval power spread out wide across islands in the world's largest ocean, key islands could be taken (such as Leyte) to cut off supply lines and bypass major bases such as Rabaul and Truk Lagoon; examples of such campaigns included Operation Cartwheel. At the end of World War II the Japanese still held most of their conquered possessions in China and Southeast Asia until the Soviet intervention.