I suppose you are referring to The Cold War. That was not a war in which nations did formal declarations of war but rather it was understood and they played a 5 decades long game of arm race, spying and making threats (such as the Cuban Missile Crisis.) Anyway Stalin was the leader of the Soviet Union when the Cold War started during the last months of World War 2.
The US Civil War was an un-declared war.
No because US never has declared war of the Soviet Union/ Russia.
The US Constitution provides that the congress shall declare war. The congress declared war on Germany when Woodrow Wilson was president in 1917 and when Franklin Delano Roosevelt was president in 1941.
george washington
George W. Bush
William Mckinney
He declared war.
President Franklin Delano Roosevelt was president when World War II began.
Germany declared war on the US on 11 December 1941. In the hopes that Japan would declare war on Russia.
That was Franklin Delano Roosevelt. He was President from March 4, 1933, until he died on April 12, 1945. The US declared war on December 8, 1941.
According to Article 1, Section 8 of the Constitution, Congress has the power to declare war. But the President is the commander-in-chief of the armed forces.
President Woodrow Wilson declared war on German in World War 1 and was in office during the war.