of Shumshu totaled up to 1,567, and the Japanese suffered 1,018 casualties, making Shumshu the only battle in the 1945 Soviet–Japanese War in which Soviet losses exceeded those of the Japanese, in stark contrast to overall Soviet-Japanese casualty rates in land-based fighting in Manchuria. During World War II, the Japanese had a naval base at Paramushiro in the Kuril Islands and several bases in Hokkaido. Since Japan and the Soviet Union maintained a state of wary neutrality until the Soviet declaration of war on Japan in August 1945, Japanese observers based in Japanese-held territories in Manchuria, Korea, Sakhalin, and the Kuril Islands constantly watched the port of Vladivostok and other seaports in the Soviet Union. According to Thomas B. Allen and Norman Polmar, the Soviets had carefully drawn up detailed plans for the Far East invasions, except that the landing for Hokkaido "existed in detail" only in Stalin's mind and that it was "unlikely that Stalin had interests in taking Manchuria and even taking on Hokkaido. Even if he wanted to grab as much territory in Asia as possible, he was too much focused on establishing a beachhead in Europe more so than Asia." Estimated casualties Because the U.S. military planners assumed "that operations in this area will be opposed not only by the available organized military forces of the Empire, but also by a fanatically hostile population", high casualties were thought to be inevitable, but nobody knew with certainty how high. Several estimates were made, but varied widely in numbers, assumptions and purposes, which included advocating and opposing the invasion. The estimated casualty figures later became a crucial point in postwar debate over the atomic bombings of Hiroshima and Nagasaki. On 15 January 1945, the U.S. Army Service Forces released a document, "Redeployment of the United States Army after the Defeat of Germany." In it, they estimate that during the 18 month period after June 1945 (that is, through December 1946), the Army would be required to furnish replacements for 43,000 dead and evacuated wounded every month. From analysis of the replacement schedule and projected strengths in overseas theaters, it suggested that Army losses alone in those categories, excluding the Navy and Marine Corps, would be approximately 863,000 through the first part of 1947, of whom 267,000 would be killed or missing. This likewise excludes wounded who would be treated in-theater during an initial window of 30 days, later