Modern international conflict increasingly involves non-state actors, yet the influence of the private sector, particularly within asymmetric disputes involving middle powers amidst great power competition, remains under-analyzed. This chapter investigates how the private sector shapes strategic environments and conflict dynamics in such contexts. These actors exert critical influence through economic, informational, and elite network mechanisms, affecting state resilience, strategic calculus, and escalation pathways. Developing a framework analyzing conditions, mechanisms, and impacts, this research employs a case study of the Philippines in the South China Sea (SCS) conflict, supplemented by a novel Private Sector Influence Index (PSII). Findings reveal how the Philippines’ oligarchic structure creates vulnerabilities but also enables elite resistance to foreign influence. The case challenges interdependence theories, highlighting robust domestic governance as crucial for managing elite influence and external pressures.