Here is a likely scenario of what would happen if Turkey declared war on Germany in the early years of the war:
1940 - Turkey joins the allies in their war against Germany.
October 1941 - Germany invades Turkey.
November 1941 - Turkey is annexed by Germany. A puppet fascist government is installed.
January 1942 - Germany uses access through Turkey to strike at the virtually undefended middle east, to gain oil and other resources.
April 1943 - Germany now has a new front with which to attack the Soviet Union.
June 1945 - The Soviet Union makes it's last stand in the Ural mountains, and fails.
March 1947 - Germany, who is now in control of all of Europe, invades the United States across both the Atlantic, and across the Bering Strait.
May 1947 - Germans enter the abandoned American Capital unopposed. The United States detonates an atomic bomb, killing the German army there.
June 1947 - Germany and the United States sign a peace treaty.
April 1950 - The United States, Canada, Mexico and all other remaining democracies unite in an alliance agaisnt any future war with Germany.
1951 - Germany detonates her first atomic bomb in Siberia. A cold war between The Western Hemisphere Alliance and the Axis sets in.
1955 - Imperial Japan and Germany go to war over control of Eurasia.
1956 - With Japan facing defeat, the Western Hemisphere alliance enters the war against Germany. World War 3 begins.
All because Turkey wanted to "help" the Allies.
A hypothetical scenario. I was bored.
