History, for most parts, is the account of the ruling classes. There was a time when philosophy encompassed almost every subject from history and physics to economics and medical studies. No wonder, lines dividing many a subject appear blurred in the works of the masters, from Plato's The Republic and Kant's Critique of Pure Reason to Hippocrates' theory on medicine and Adam Smith's The Wealth of Nations. Their works were welcomed because they didn't pose a threat to the ruling classes, for none of them saw human labor as a decisive factor in social and economic development. True, L.H. Morgan dealt with it in his Ancient Society, which later formed the basis of Engels' The Origin of Family, Private Property and State.
But 36 years before The Origin was published, Engels joined Marx to write the Manifesto of the Communist Party, which gave birth to Marxism and exposed, for the first time, the ruling classes as exploiters of labor. The ruling classes instantly saw it as a threat, and haven't seen a greater one to this day.
The world, rather the capitalist world, has undergone radical change since 1948, when the Manifesto was published. Capitalism has become more dynamic, made many theories and philosophies its own and declared democracy to be its most potent weapon. It wouldn't be unfair to assume that to the West democracy means a capitalist form of government. One thing that has not changed, however, is that capitalism still sees Marxism as its greatest threat.
The praxis of Marxism may have had some flaws, mainly because leaders of Communist states undermined the power of external (read capitalist) forces working against them. But then which leader or government in human history (most of it dominated by exploiters and oppressors), except perhaps the Paris Commune, can claim to have been infallible.
True, countries ruled by communists have had their flaws. But putting the blame on one (the erstwhile Soviet Union) for starting World War II is not pointing at one of those flaws; it is inventing a blatant lie, a violent attempt at rewriting history a perfect example of palimpsest.
Seventy eventful years have passed since Hitler invaded Poland, triggering WWII. History, even those penned by the ruling classes in the West, tells us Hitler, along with Mussolini and Hirohito, started the war. He used the Spanish Civil War as a dress rehearsal (sic) for WWII, while the rest of the West enjoyed the comforts of its non-interventionist policy. The leaders of rest of Europe watched amusingly as Hitler occupied Austria and dismembered Czechoslovakia because they believed the Bolsheviks were the real enemy.
Stalin may have committed some mistakes but sending Vyacheslav Molotov to sign a non-aggression treaty (between the Soviet Union and Germany) with Joachim von Ribbentrop wasn't one of them. Present-day Polish rulers, however, think otherwise, alleging that it was Soviet troops that actually stared WWII by attacking Poland as part of a plot with the Germans to carve out Eastern Europe into Soviet and Nazi territories. And, they allege, the Molotov-Ribbentrop treaty was a precursor to that. They don't dare say Poland, too, had signed a non-aggression pact with Germany that the Soviets realized was aimed at destroying their country.
Poland today is a member of the European Union and the NATO. And it was the Organization of Security and Cooperation in Europe (OSCE) that equated Stalin with Hitler first and blamed both of them for starting WWII. Poland is in a hurry to be part of the West, intellectually and politically. And the West, which is essentially and politically capitalistic, would go to any length to condemn Marxism because it sees it as its greatest enemy.
The OSCE and Polish accusations are not a condemnation of Stalin alone but an attempt to malign everything related to Marxism. The very fact that an Allied victory would not have been possible without the great Soviet sacrifice, however, condemns the aspersions to the trash bin of the very history that West itself has created.
If still in doubt about the double standards of European countries and the US during WWII, please refer to Michael Sayers and Albert E, Kahn's (both American journalists) The Great Conspiracy: The Secret War Against Soviet Russia.