The question is fundamentally flawed.
America hasn't had a ruler since it's revolution. The Constitution is the supreme law of the land. Every elected and appointed official takes an oath to "protect and defend the Constitution." The author of the Constitution is identified in the first three words, "We the people"
This puts Lincoln's words, "A government of the people, by the people, for the people" into perspective.
The President is one of many elected officials who are granted certain limited powers by the Constitution. Article II defines the power of the President.
During World War II, Franklin Roosevelt held the office of President, until he died in 1944, and was promptly replaced by Harry Truman.
France
In world war 1,germany started the war,but in world war 2,japan started it and usa ended the war
Commandants ruled large areas. For example a commandant could have ruled Auschwitz. A commandant was very high in power.
The USSR was a communist government with Josef Stalin as its leader during World War 2. Stalin ruled as a dictator and was responsible for the deaths of millions he ordered killed.
America.go USA
No countries ruled Berlin after world war 2
The Emperor ruled Japan.
France
I think Croatia was still ruled over by Austria-Hungary but they may have been independent after World War I :)
The British
Adolph Hitler
King Boris III.
France
Bailey Cross
France
Adolf Hitler .
Taisho.