In the first half of the 20th century, a number of socialists in the United States began to hold the view that the Soviet government was becoming a red fascist state. One such leader, Norman Thomas, who ran for President numerous times under the Socialist Party of America banner, accused the Soviet Union in the 1940s of decaying into Red fascism by writing: "Such is the logic of totalitarianism", that "communism, whatever it was originally, is today Red fascism". Bruno Rizzi, an Italian Marxist and a founder of the Communist Party of Italy, claimed as early as 1938 that "Stalinism [took on] a regressive course, generating a species of red fascism identical in its superstructural and choreographic features [with its Fascist model]".
Many leftists in the 1930s and 1940s became disillusioned by and estranged from the Soviet Union, condemning it for its rigid authoritarianism. Otto Rühle, a German left communist, wrote that "the struggle against fascism must begin with the struggle against bolshevism", noting the possible influence the Leninist state had on fascist states by serving as a model. In 1939, Rühle further professed:
Russia was the example for fascism. [...] Whether party 'communists' like it or not, the fact remains that the state order and rule in Russia are indistinguishable from those in Italy and Germany. Essentially they are alike. One may speak of a red, black, or brown 'soviet state', as well as of red, black or brown fascism.
In a September 18, 1939 editorial, The New York Times reacted to the signing of the Molotov–Ribbentrop Pact by declaring that "Hitlerism is brown communism, Stalinism is red fascism". The editorial further opined:
The world will now understand that the only real 'ideological' issue is one between democracy, liberty and peace on the one hand and despotism, terror and war on the other.
During the period while the Molotov–Ribbentrop Pact was in force, Benito Mussolini positively reviewed Stalinism as having transformed Soviet Bolshevism into a Slavic fascism. Despite ideological differences, Adolf Hitler admired Stalin and his politics and believed that Stalin was in effect transforming Soviet Bolshevism into a form of Nazism. After being opponents for most of the 1930s, the Soviet Union and Nazi Germany signed the Molotov-Ribbentrop Pact in 1939 and remained aligned for the first two years of World War II, until Hitler broke it by invading the USSR in 1941.
Marxist theories of fascism have seen fascism as a form of reaction to socialism and a feature of capitalism. In addition, several modern historians have tried to pay more attention to the economic, political and ideological differences between these two regimes than to their similarities. Although Michael Geyer and Sheila Fitzpatrick in Beyond Totalitarianism: Stalinism and Nazism Compared (2009) noted similarities between Stalinism and Nazism, they have also stated that "when it comes to one-on-one comparison, the two societies and regimes may as well have hailed from different worlds". By contrast, David Ramsay Steele posits that "there is a close ideological relationship between Marxism and Fascism". When Nazi Germany aligned itself with Communist Russia in 1939, British journalist John Gunther happened to be working in Moscow. He wrote in his 1940 book Inside Europe that "certain shrewd observers had seen which way the wind was blowing. They had seen that Communism and Fascism were more closely allied than was normally understood."
In his 2008 book Left in Dark Times, French philosopher and journalist Bernard-Henri Lévy has used the term in arguing that some European intellectuals have been infatuated with anti-Enlightenment theories and embraced a new absolutist ideology, one that is anti-liberal, anti-American, anti-imperialist, antisemitic and pro-Islamofascist.