John McGrath's The Other End of the Spear is a timely historical analysis and an important follow-on work to his earlier analysis of troop density trends in CSI Occasional Paper 16, Boots on the Ground. As that work showed, this paper also shows the timeless value of history and its relevance to current events. Boots on the Ground analyzed the ratio between the numbers of troops employed in military operations relative to the population in a number of irregular conflicts. This study analyzes the composition of such forces to answer the question, what have been the historical trends in the ratio of deployed forces directly engaged in fighting, relative to those engaged in non-combat functions? This ratio is commonly, if inaccurately called the tooth-to-tail ratio.