The Allied powers who defeated Nazi Germany in World War II divided the country west of the Oder-Neisse line into four occupation zones for administrative purposes during the period 1945–1949. In the closing weeks of fighting in Europe, American forces had pushed beyond the previously agreed boundaries for the future zones of occupation, in some places by as much as 200 miles. The line of contact between Soviet and American forces at the end of hostilities was temporary. After two months in which they had held areas that had been assigned to the Soviet zone, American forces withdrew in July 1945. Some have concluded that this was a crucial move that persuaded the Soviet Union to allow American and British forces into their predesignated zones in Berlin, which occurred at roughly the same time (July 1945), although the need for intelligence gathering (see Operation Paperclip) may also have been a factor.