This article analyzes American artists’ opposition to the war in Iraq, emphasizing the way it was determined by their professional situations. Regardless of the networks and political organizations involved, or the ideological dimensions of the anti-war cause, individual professional identities and relationships persisted and influenced their public practices and positioning. In a first section, we compare different artistic subfields and labor configurations, to grasp what, in the participants’ own eyes, made the combination of artistic and militant identities - and, sometimes, the production of a form of “political art” - tenable. The second section concentrates on how political commitment emerged in fields of professional activity, how the functioning of artistic milieus today – that have become more autonomous, specialized and professional – tends to discourage “mixing registers”, i.e. combining aesthetic motives and political logics.