Uncontested US supremacy established with the dissolution of Soviet Union in 1991 is fast drawing to a close. Impending power transition in the global hierarchy has triggered post-hegemonic phase in the international system. This transition of power in the global order has marginalized US military interventionist policy. The “rise of China” along with alternate power centers has considerably constrained US clout to obtain “desired outcomes.” These systemic changes apart from inducing drift away from US led and controlled patterns of interaction and exercise of influence, have altered shape of the existing international system and brought additional actors with increasing sway on political outcomes. Besides, the drift towards post-hegemony send strong signals to local / regional hierarchies where “challengers” try to take advantage of the vulnerability prevailing in the global hierarchy. Such regions with significant changes in regional structure and hierarchy give rise to great power intervention dynamics made possible through conflict, instability and erosion of traditional structures of power. One such region is MENA (Middle East and North Africa) after the unprecedented Arab Spring upheavals, where a clear de-link from previous US hegemonic practices could be observed. These regional hierarchies with diffused power structures are significant in establishing the link between global and regional hierarchies in post-hegemony, explored in the study through extension of Power Transition Theory research program. The arrival of post-hegemony also alters military intervention behavior of the declining hegemon that has to rely on “securitization of threat” through “political discourse” as enunciated through case studies of Libya and Syria by employing Securitization Theory and Discourse Analysis Approach. The study seeks to substantiate not only the dawn of post-hegemonic phase in the international system but validate “threat securitization military intervention model” developed within the study to explore the link between MENA and global power hierarchy in transition, and significance of discursive construction of “threat” for foreign direct military intervention The rise of peer challengers, US “back-seat role” in Libya and its incoherent and inconsistent foreign policy approach towards Syria has exposed US limitation to influence and direct events on the international stage, increasingly frustrating acquisition and implementation of US policy goals in key regions like MENA. The study affirms that power transition in the global order has introduced post-hegemonic system that has marginalized US unilateral interventionist policy on the use of force.