Japan,Germany,Soviet Union,Great Britain,France,Italy, in according to their responsibility and the extent of harm they did on the war.
(Note: This order is what my opinion is, if there is wrong, please rearrange it.)
Japan- Killed (Murder) , Raped many people across parts of Asia (Eastern China- Near coastal lines and South East Asia except Thailand). A main part of the War and the last one to surrender as well as started the war in Pacific.
Germany- Killed Jews (6 million estimated.) and started the war in Europe.
Soviet Union- Signed the treaty of Nazi-Soviet pact where not only Soviet agreed to stay neutral even in times of war but also divided their so-called "spheres of influence" in the Central and Eastern Europe. This gives Hitler even bolder to wage a war as Hitler knew that he was not going to fight a 2 front war which caused the easy defeat of Germany during World War 1 (Before Nazi's regime). On the Soviet side, the pact resulted in aiding Germany in the invasion on Poland - the Red Army also invaded Poland from the east on September 17 1939. Furthermore, it soon invaded south-eastern Finland and occupied Lithuania, Latvia and Estonia. In June 1941, the Nazi-Soviet political and military cooperation has ended with the German invasion on the Soviet Union. The Russians, along the other nations of the Soviet Union, did have the causalities of nearly millions as the result of these actions.
Great Britain- Churchill keeps believing Hitler (The leader of Nazi Germany) is reliable and kept to his promise even after he betrayed all of his promise. (One example: Hitler wants Sudetenland that is German majority and border of Czech-Germany and did not intend the whole of Czech but 6 months after he got it, he full scale invaded Czech and took all of it because Czech was disarmed and thought there would be peace after appeasing him.)
France- Being supportive of Britain. The policy of Appeasement that gives Hitler bold to demand more. France was lated defeated by Hitler without having causalities of millions of the population.
Italy- Although Italy started the war in Africa mainly and participated war in Europe, she did not took all of Africa continent and mainly what she got was some parts of Middle East and some Northern parts of Africa.
Germany
The Second World War begun when Germany invaded Poland. So Germany is responsible for starting the war.
Germany.
imperialism
World War 2 : Japan.
Germany.
poland
in what country did the world war 2 start and what were the allies?
Germany
Depends on which country you mean
polish
georges fat right nostrel