Fulda Gap

The Fulda Gap , an area between the Hesse-Thuringian border and Frankfurt am Main, contains two corridors of lowlands through which tanks might have driven in a surprise attack by the Soviets and their Warsaw Pact allies to gain crossing of the Rhine River. Named for the town of Fulda, the Fulda Gap became seen as strategically important during the Cold War of 1947-1991. The Fulda Gap roughly corresponds to the route along which Napoleon chose to withdraw his armies after defeat at the Battle of Leipzig. Napoleon succeeded in defeating a Bavarian-Austrian army under Wrede in the Battle of Hanau not far from Frankfurt; from there he escaped back to France.

From 1815, the area appeared of minimal strategic importance, as it lay deep within the borders of the German Confederation and of the German Empire, and German military planning presumed any war would be effectively lost long before an enemy reached that far into the homeland. The route became important again at the end of World War II when the U.S. XII Corps used it in their advance eastward in late March and early April 1945. The U.S. advance had little consequence for Germany's strategic position , but it allowed the Americans to occupy vast swaths of territory which the Yalta Conference of February 1945 had assigned to the Soviet occupation zone. This in turn did much to compel the Soviets to honor their commitment to allow the Western Allies access to Berlin in exchange for U.S. withdrawal from this territory.

Wikipedia