With the complexity of the international system and being in a state of transition, the evolution of regional systems and the foreign policy of countries requires structural adaptation to the strategic requirements of such a transition. What springs from these developments is that the classical analytical thinking of regionalism and the linear conception of foreign policy does not meet the complexities of the uncertainty age. Therefore, this fundamental question has been raised as the present study's direct engagement: How will Iran's foreign policy strategy as a multi-neighboring country with diverse and heterogeneous ones be reconstructed in the context of a complex international system? The paper's major reason lies in multiplex networked regionalism that will serve us as a suitable theoretical model so well to go beyond the linear thinking to the region and outline proactive regionalism based on multi-neighborhood foreign policy. Research findings by using the abduction method, show that drawing Iran's multiplex networked regionalism requires putting innovative and adaptive strategic diplomacy on the agenda and drawing a strategic partner’s map based on smart synerg, which emphasizes the equifinality and dynamic equilibrium between Geopolitics, Geo-economics, and Geo-cultural dynamics.