This book provides a comprehensive historical and institutional foundation for understanding the shifting power dynamics within the contemporary Indo-Pacific and East Asia. It examines the region s complex security architecture, focusing on the U.S.-led alliance system, ASEAN-centric multilateralism as well as China-led multilateralism, and emerging minilateral networks to explain how regional stability is maintained. The narrative moves beyond a simple overview, tracing the evolution of these institutional frameworks over decades. The chapters explore how the interplay between traditional bilateral alliances and modern diplomatic forums has created a unique security order. Rather than focusing on just one aspect, the text highlights how these different mechanisms adapt to rising tensions and strategic competition. By analyzing the historical roots of these relationships, the volume provides the essential context needed to understand the deeper rivalries shaping the region today. As the first part of a two-volume study, this research establishes the analytical groundwork for understanding regional order. It serves as an indispensable guide for anyone looking to grasp the foundations of great-power competition before exploring the specific Sino-Japanese visions for the future addressed in Volume II.