the Axis powers in both the Atlantic and Pacific simultaneously. Rainbow plans Japan had used the opportunity afforded by World War I to establish itself as a major power and a strategic rival in the Pacific Ocean. After the war, most American officials and planners considered a war with Japan to be highly likely. The fear lessened when the civilian government of Japan temporarily halted its program of military expansion, which was not to resume until 1931. War Plan Orange was the longest and most-detailed of the colored plans. However, following the events in Asia in 1937 (the Second Sino-Japanese War) and Europe in 1938—1940 (the Anschluss, the Munich Agreement, the German occupation of Czechoslovakia, the Molotov–Ribbentrop Pact and the German invasion of Poland and Western Europe), American war planners realized that the United States faced the possibility of war on multiple fronts against a coalition of enemies. Therefore, the Joint Planning Board developed a new series of war plans, the "Rainbow" plans—the term being a play on the multiple "color" plans that had been drawn up previously. Rainbow 1 was a plan for a defensive war to protect the United States and the Western Hemisphere north of ten degrees [south] latitude. In such a war, the United States was assumed to be without major allies. Rainbow 2 was identical to Rainbow 1, except for assuming that the United States would be allied with France and the United Kingdom. Rainbow 3 was a repetition of the Orange plan, with the provision that the hemisphere defense would first be secured, as provided in Rainbow 1. Rainbow 4 was based on the same assumptions as Rainbow 1, but extended the American mission to include defense of the entire Western hemisphere. Rainbow 5, destined to be the basis for American strategy in World War II, assumed that the United States was allied with Britain and France and provided for offensive operations by American forces in Europe, Africa, or both. The assumptions and plans for Rainbow 5 were discussed extensively in the Plan Dog memo, which concluded ultimately that the United States would adhere to a Europe first strategy in World War II. Leak of the Rainbow 5 plan On December 4, 1941, three days before the Japanese attack on Pearl Harbor, the Chicago Tribune, with the headline "F.D.R.’s War Plans!", along with The Times Herald of Washington, D.C., published the Rainbow Five plan.