美新版《国防战略报告》转向明显：国土安全成首责，对中俄表述温和

Core Insights - The 2026 National Defense Strategy Report emphasizes homeland security as the top priority for the Pentagon, marking a significant shift in U.S. defense policy since 2022 [1][5] - The report calls for allies to take on more responsibility in defense matters, reflecting a transition from a leadership role to a limited support role for the U.S. [2][12] - The approach towards traditional adversaries, particularly China and Russia, has softened, focusing on deterrence rather than confrontation [4][5] Summary by Sections Homeland Security and Strategic Shift - The report prioritizes the defense of the U.S. homeland and aims to restore military dominance in the Western Hemisphere, rejecting previous abstract goals like nation-building and democracy promotion as burdensome [1][2] - The strategy reflects a deep military strategic shift from global competition to a focus on "America First" and domestic defense [2] Changes in Threat Assessment - The report redefines the primary threat, placing "U.S. homeland and Western Hemisphere security" at the highest priority, moving away from labeling China as the "primary challenge" [2] - It emphasizes a new security perspective where the border is considered a battlefield, with military technology being used to enhance border security [2] Defense Industrial Base and Investment - The U.S. plans to invest $500 billion over five years to upgrade its defense industrial base, including missile defense systems and military production capabilities [3] - The "Iron Dome" missile defense system, now referred to as "Gold Dome," is part of this initiative, aiming to integrate with existing capabilities to intercept missiles from various sources [3] Relations with Allies - The report establishes a "transactional alliance" model, urging allies to take on more defense responsibilities while the U.S. provides limited support [12][13] - It indicates that NATO allies are capable of handling conventional defense in Europe, with the U.S. playing a more supportive role [13] Regional Military Developments - The U.S. is enhancing military bases in the second island chain and deploying advanced missile systems in the region, indicating a continued focus on military readiness in the Indo-Pacific [8][9][11] - The report notes that the U.S. will reduce its direct military presence in regions like the Korean Peninsula, shifting more responsibility to South Korea [13]