In the USA, a nationwide “Red Scare,” fueled by strikes, bombings and labor unrest, occurred shortly after WWI. Civil liberties were trampled and dissidents arrested as the nation feared a Bolshevik revolution. But, unlike Japan where suppression of leftist ideology accelerated, American attitudes soon relaxed and the great Red Scare abated.
In the early 1920s, left wing parties in Japan were generally banned or suppressed by the government and military. In 1928 a serious government crackdown resulted in the arrest of many socialists and communists. Thereafter, communism was forced completely underground.