ABSTRACT This paper explores the relationship between Britian’s abolition of slavery in its Caribbean colonies in 1838 and its instigation of the First Opium War with China in 1840. In so doing, it works against the occlusion of this relationship in the study of British imperialism despite the centrality of these events to the birth of global systems of free trade and free labour. It draws on the parliamentary debates and correspondence of British Foreign Secretary Lord Palmerston to analyze Britain’s negotiation of anti-slavery efforts with Haiti and its trade of Indian opium with China. It argues that these negotiations position British masculine civility against less-civilized foreign others in ways that legitimate the use of maritime force. This logic of imperial civility produces contradictory effects by demanding an end to the brutality of African enslavement while condoning the devastation of Asian opium addiction enacted in the name of free trade.