During the 20th century abstract art was often connected with radical politics, most famously in the work of the Constructivists in post-revolutionary Russia. Although few would argue today that there is an inherent connection between abstract art and left-wing opposition, there is little awareness of how abstract art could also be complicit with Fascism, as happened in the 1930s in Italy. This lack of awareness can be partly credited to the role that Italian art historians have played in suppressing this complicity by publishing altered documents in exhibition catalogues. Drawing on research conducted in Italy and the United States, this paper will investigate this important and little known aspect of 20th century abstract art and its historiography, and explore a number of issues arising from it. Chief among these will be the ramifications for our understanding of abstract art's 'critical' role, and the ethical problems faced by modernist art historians and curators dealing with the legacy of fascism.