Wild male olive baboons (Papio anubis) used females and infants as agonistic buffers. Male residency status determined whether a male used females or whether they were used against him. The success of the strategy depended on the cooperation of the female and the context of the interaction. Female cooperation correlated with preexisting social affiliation with the male user. Male choice of female or infant buffers represented a compromise between the potential effectiveness of each in different situations and the social and spatial availability of females and infants. Nonreproductive social relationships may provide long-term strategic benefits to the individuals who invest in them.