Abstract This article discusses the problem of evaluating socio-political interventions in language at the case of Croatian. From a theoretical point of view, definitions of such interventions, often called purism, are first analyzed and placed in the context of the ‘one standard axiom’ thesis. To determine why only some historical periods of intervention are labeled as purist, a brief comparative overview is provided of conflicting perspectives on interventions in the Croatian language made between 1918 and 1990. The author argues that partial historical analyses will always find that a particular regime pursued a policy of purism. Moreover, proponents of the Yugoslav period as normal adhere to the thesis of the existence of the ‘One Standard Bosnian, Croatian, Montenegrin, and Serbian Axiom,’ while their counterparts argue for the distinctiveness of the Croatian language from related South Slavic languages.