Australia and Papua New Guinea’s Pukpuk Treaty is not just about keeping China at arm’s length. Security investment can underpin broader economic growth by strengthening governance, reducing crime and improving investor confidence. The Pukpuk Treaty should not be viewed narrowly as geopolitics or only as an act of denying China space. In strengthening the PNGDF, Australia is making a timely investment to help PNG address its demographic pressures and internal security stresses. If these efforts falter, the alternative could be far costlier for PNG, Australia and indeed the entire Pacific.