ABSTRACT This study challenges common-sense thinking on internal violent conflicts in two ways: that they are merely domestic, with limited influence from external actors; and that doing business in conflict-ridden places is detrimental to profits. Drawing on empirical research and theoretical lenses from critical security studies and the political ecology of counterinsurgency, the paper explores the transnational dimensions of Colombia’s violent conflict in relation to the extractive sector. Conceptualising two overall generations of counterinsurgency, the article shows how, during the conflict, several transnational corporations, especially those in the extractive and agro-industrial sector, not only established themselves in Colombia and expanded, they also developed their corporate security schemes. Given that energy projects were strategic targets in the guerrilla war, the protection of corporate infrastructure by the state was justified. The paper argues that the internal conflict not only facilitated corporate extractivism, it also provided innovative ways of ensuring corporate security. This ‘social warfare’ approach includes strategic efforts to win hearts and minds, which continue to be pursued today through practices known as ‘corporate social responsibility’ (CSR). The paper relates this to the current challenges to hold economic actors accountable in transitional justice.