Border states is a term referring to the European nations that won their independence from the Russian Empire after the Russian Revolution, the treaty of Brest-Litovsk, and ultimately the defeat of the German Empire in World War I. During the interwar period the nations of Western Europe implemented a border states policy[1] which aimed at uniting these nations in defense against the Soviet Union and communist expansionism. The border states were Finland, Estonia, Latvia, Lithuania, Poland, Romania, and, until their annexation into the Soviet Union, Belarus and Ukraine.
The policy tended to see the border states as a cordon sanitaire, or buffer states, separating Western Europe from the newly formed Soviet Union. It was never particularly successful, however; disputes and different allegiances between andwithin the group of states hindered unity. The matter was further complicated by the rise of the expansionist Nazi Germany. In 1939 Germany and the Soviet Union signed the Molotov-Ribbentrop Pact, which effectively divided the territory of the border states between those two countries. With the exception of Finland, all border states fell under Soviet occupation as a result of World War II.