I explore the construction of women as the secret for the 'successful' prosecution of war in Afghanistan. To do so, I take up the mobilization of gender in the US counterinsurgency doctrine as deployed in Afghanistan. I draw on the 2006 Counterinsurgency Field Manual, human rights and humanitarian reports, and scholarly works to identify and analyze this mobilization, paying attention to the colonial histories upon which COIN explicitly and implicitly relies. By critically integrating these sources and the paradigmatic moments that exemplify COIN, I demonstrate the constitutive relationship of gender and COIN. The valence of the secret - of women as concealing, revealing, being, and bearing the secret - is still a lesser explored element in the analysis of the gendering of COIN and of its 'military orientalism'. Even as scholars have powerfully shown how, in the case of Afghanistan and elsewhere, the veil functions as an overdetermined and 'multilayered signifier' in its own right, symbolizing the 'tension between disclosure and concealment that defines the dominant conception of the secret', less subject to detailed analysis in case of Afghanistan is the ways in which Afghan women are constituted through COIN in polysemous relation to the notion of the secret.