This page outlines common critiques of the actions of the allies during World War II from a non-fascist perspective.
Bombing of Cities
The bombing of civilians and cities during World War II has been heavily criticised as unnecessary, notably the nuclear bombings of Japan.
Collaboration with Nazis
Both the USA and USSR attempted to recruit former Nazis and often shielded them from criminal prosecution so they could be used as agents during the Cold War. While this most famously happened with Operation Paperclip - the recruitment of Nazi scientists for research purposes, there were also cases of Nazis being recruited to instruct the secret police of pro-western dictatorships in torture methods and recruited to engage in terrorism for a variety of pro-American reasons.
Ideological Exploitation
Some have accused Allied nations of cynically exploiting the respect they've gained from defeating Hitler as a justification for further, less just wars like in Vietnam and Iraq.
Oppression of Ethnic Minorities
Throughout the war, allied nations carried out oppression of ethnic minorities in their own countries due to fears that they would sympathise or collaborate with Nazi Germany or the Japanese Empire. Whether or not this was motivated by racist thinking or was used as a cynical excuse to crush political opposition or was justified is still a matter of heavy debate. Although, as libertarian socialists, we tend to lean towards the first two explanations.
War Crimes
The allied forces committed a variety of war crimes throughout the war which have been heavily criticised.