This article explores the role that ground troops play in aerial campaigns. Specifically, it intends to explain how ground troops affect the duration of aerial bombing campaigns. It distinguishes between the effect of ground troops on the duration of aerial campaigns that are selective and on those that are more general and less discriminate (using newly coded data on aerial strategies). The effect of ground troops may vary depending on how air power is being used. Ground troops may increase the duration of aerial campaigns in cases in which selective strategies are used during the aerial bombing campaign. In these cases, states lose the possibility of quick, “clean” victories once ground troops are introduced. In the cases of the less-discriminate bombing campaigns, the effect of ground troops is the opposite: They shorten the duration of the bombing campaign, possibly through the increased effectiveness of a combined arms approach.