The Baltic states of Lithuania, Latvia, and Estonia were part of the Russian Empire during the 19th century, achieving independence in the aftermath of World War I. The rise of Nazi Germany during the 1930s created Russian fears of a German invasion.[3] The Soviet Union signed the Molotov–Ribbentrop Pact with Germany in August 1939, in part as an attempt to delay this possibility.[3] Germany shortly initiated World War II by invading Poland on September 1.