特朗普2.0时期美国国防战略调整的动机及困境OACHSSCD

The National Security Strategy released by the Trump administration formally declares,for the first time in official text,the irreversible end of the United States post-Cold War unipolar hegemony.It elevates"America First"to the supreme guiding principle of national security and conducts a systematic reckoning with the strategic paradigm—prevalent since the end of the Cold War—of maintaining global hegemony and indefinitely expanding the"liberal international order".This document establishes fundamental constraining conditions for the subsequently released National Defense Strategy,thereby triggering a comprehensive restructuring across multiple domains:alliance relationships,operational doctrines,force posture,the military-industrial system,geopolitical pivot points,and technological pathways.This transformation represents a hegemonic power's proactive strategic rebalancing to reshape the rules of the international order in an era of power diffusion,rather than a mere passive adaptation to the structural pressures of multipolarization.While it perpetuates the traditional American cycle of expansion and contraction,it achieves a paradigm-level historical rupture in its core dimensions.Through pathways such as the contractualization of alliance relationships,prioritization of independent combat capabilities,fortification of key nodes,localization of national defense mobilization,construction of a new military-industrial complex,and the weaponization of strategic resources and technical standards,the United States aims to achieve a structural reduction in the costs of sustaining hegemony alongside a non-symmetric leap in effectiveness.More critically,does this highly refined rebalancing system inherently contain deep-seated tensions and implementation paradoxes capable of undermining its long-term sustainability?Through a retrospective examination of historical context,deconstruction of the strategic framework,and analysis of contemporary dilemmas,this article seeks to explore the true structural implications of this round of defense strategic reshaping.