Interactions of rising powers and established powers and their implications in peacebuilding and security remain underexplored in existing literature. This paper aims to explore inferences of the behaviour of Brazil, China and India in peacebuilding and security, their contention and cooperation with the US and European powers, and implications for the global south. It analyses their interactions in the light of democratic peace propositions, adhered to by established powers, and the regional security complex theory pertinent to the ascendancy of new powers. Though liberal countries are co-opting emerging actors, the responses of rising powers to international security issues appear inconsistent and unpredictable. With increasing material capabilities, rising powers have been creating a patron–client relationship with conflict-affected states, because of which this article disconfirms possibilities of a sometimes anticipated pro-south world order.