© 2021, The Author(s), under exclusive license to Springer Nature Switzerland AG.This research is based on explaining the dynamics that led the Iran, Russia and Turkey to initiate Astana Process within the framework of the Syrian Civil War’s changing dynamics. The article intends to combine power politics with the “complexity” paradigm. Linear ontology is problematic in explaining the changing dynamics. On the other hand, the complexity paradigm explains non-linear processes derived from its ontological foundation. Especially the variety and diversity of actors, their interconnection, interdependence, and co-adaptation to the situation can be a solution against the reductionism of this phenomenon. Actors in the Syrian crisis are very diverse, and it can be observed that actors like ISIS can profoundly affect the policies in this process, and the Syrian issue can affect varied actors’ security and foreign policies that are also based on power competition. Complexity paradigm assumes system as complex, more dynamic and living that many actors (which are not exogenous as closed units) interact with many feedback loops; thus the outcome of the events may not be predicted. IR is also impacted by many various parameters and variables which are interconnected and interdependent, indeed, also the main actors in the system cannot be limited by only states which are socializing and affected by the structure in their interactions considering the critical impact of the substate factors, transnational terrorist groups, and many other variable causes as well as their interactions in the international changing and co-evolutionary dynamics. Russia, Turkey, and Iran (the guarantors of the Astana Process) have followed different policies and demonstrated divergent outlooks regarding the crisis. Indeed the priorities and set agendas differed from one another as well as objectives to pursue in the disorder occurred by fragmented and diversified dynamics in Syria. However “unpredictable” events of changing dynamics resulted in diversification of states’ agendas. The prolongation of the civil war led to the introduction of new actors along with it, and especially the states sharing the border with Syria were also exposed to new threats. It can be seen that with the emergence of ISIS and Russian activism in the Syrian complexity, especially her intervention in Syria as well as other actors’ policies on this complexity, the regional and global powers have also co-adapted their policies on the changing dynamics. This co-adaptation also derives from the intertwined causalities in the complexity which is between the order and disorder. The Astana process is also an expression of this co-adaptation in Iranian, Russian and Turkish policies in Syrian Complexity. The complexity paradigm offers an alternative framework in order to understand the process-oriented interconnected power struggle in disorder. The characteristics of the “processes” in the Syrian disorder symbolizes the fracturing component in the power struggle that brings non-linear orientation. The power struggle shaped by the non-linear dynamics by the time and processes in the changing dynamics brings about flexibility in the behaviors of the actors in order to maintain their initial priorities in their foreign policies or their main objectives in the changing dynamics. That results in the co-evolutionary dynamics in the interactions between the relative power distributed actors restrained or allowed activism in structure, and between the actors and structure that co-shaped each other in the area.