This chapter examines why and how small militaries have adopted operational art despite not possessing large enough forces to apply the concept in the manner it was originally intended. First, it establishes context by summarizing three large military operational art traditions – the German, Soviet, and American traditions. Second, it examines why small militaries have adopted the concept, positing that it is due to a mixture of interoperability and cultural reasons. While there are many potential ways to define “small militaries,” they are defined here as either comprising less than 100,000 personnel, or as fielding land combat forces of one division or less in size. By either definition, these militaries are smaller in scale than those required to apply operational art as conceptualized within the three large military traditions summarized. Third, three case studies examine how small militaries have adapted and applied the concept: those of Australia; Canada; and the Nordic and Baltic countries. Despite facing different strategic situations, the way these militaries have applied operational art has been very similar. All have taken a functional approach, which de-links operational art from its original emphasis on scale. These militaries have used this modified concept to enable them to operate more effectively alongside their larger allies, America in particular.