二战爆发初期，苏联为了自己的国家安全，不惜损害别国利益，从1939年到1940年建立东方战线，使自己能有一个防御地带。
At the beginning of the Second World War , in order to have a defensive area for the Security of Soviet Union , Soviet Union founded the Eastern Battle Line from 1939 to 1940 , although other relative countries were hurted .
防御地带