Tsar Nicholas II was the leader of Tsarist Russia in World War 1.
One of the major reasons as to why the Tsarist regime in Russia declined was as a result of the involvement of Russia in the World War I. The stability of Russia could not be underestimated.
A world power after defeating Tsarist Russia during the Russo-Japanese War 1904-1905.
== == Ukraine was not independent during WW2, therefore it did not have a leader. It was a part of Russia
Vladimir Lenin is the revolutionary leader who took over Russia in World War 1.
The most powerful leader in Russia during World War I was Nicholas II. In addition, Nicholas Nikolaevich and Aleksei Brusilov were leaders during WW1.
Josef Stalin, a dictator
Vladimir Lenin was leader of the radical socialists who took over Russia in World War 1.