This article begins by situating Muriel Rukeyser’s call for ‘the security of the imagination’ within the highly charged historical contexts of the 1940s, a decade bracketed not only by war but by America’s growing obsession with security - from President Roosevelt’s ‘Four Freedoms’ speech of 1941 to the rise of McCarthyism at the end of the forties. It then examines how Rukeyser’s work as a propagandist, a poet and an essayist in the 1940s was deeply shaped by her involvement with the American security services. It further shows how Rukeyser sought to combine words and images in both her war posters and her poems in an attempt to forge an expansive, inclusive and antifascist mode of representation. In a significant departure from other studies of this period, this article brings original archival sources into contact with Rukeyser’s poetry, and reads these literary and archival documents through the theoretical lens of security studies. In the face of an increasingly paranoid, repressive political climate, Rukeyser’s wartime propaganda work and poetry offers ways of thinking past dominant assumptions structuring the discourse of security.