与此同时，日本正透过与澳大利亚、菲律宾、印度和韩国等区域国家建立战略伙伴关系和准同盟，来使其安全网络多元化。这种「集体自治」战略旨在透过建立联合威慑和保障关键供应链，来维持一个自由开放的印太地区。然而，这种坚定的姿态引起了北京方面的强烈敌意，在北京，当首相 Sanae Takaichi 宣布中国对台湾的封锁将是一个生死存亡的威胁后，最近对日本实施了针对重型机械和造船业的经济制裁。
在国内，日本面临著威胁其长期战略可行性的严重结构性限制。其人口前景极其严峻；在 2024 年，生育率降至每位女性仅 1.1 个婴儿，远低于 2.0 的替代水平。这种永久性的人口下降将显著缩减适龄服役人口并使经济承压。此外，庞大的国防扩张，结合潜在的消费税减免和能源补贴，给国家预算带来了巨大的财政压力，冒著债券市场反弹的风险。
Japan is responding to rising geopolitical threats from China and Russia, alongside growing uncertainty regarding America’s commitment, by entering a new era of foreign policy. Since 2022, Tokyo has nearly doubled its defense budget from 1% to 2% of GDP, with plans to potentially reach 3% of GDP or higher by the early 2030s. This rapid build-up, which could elevate Japan to the world’s third-largest military budget, includes the acquisition of long-range missiles and the potential development of nuclear-powered attack submarines. To counter Chinese pressure, such as the deployment of two aircraft carriers beyond the First Island Chain last year, Japan is fortifying its southwestern islands and delaying its Tomahawk cruise missile acquisitions to 2029 due to US military distractions.
Simultaneously, Japan is diversifying its security network by establishing strategic partnerships and quasi-alliances with regional nations like Australia, the Philippines, India, and South Korea. This "collective autonomy" strategy aims to maintain a free and open Indo-Pacific by building joint deterrence and securing critical supply chains. However, this assertive posture has drawn intense hostility from Beijing, which recently imposed economic sanctions targeting heavy machinery and shipbuilding after Prime Minister Sanae Takaichi declared a Chinese blockade of Taiwan to be a vital security threat.
Domestically, Japan faces severe structural constraints that threaten its long-term strategic viability. Its demographic outlook is extremely critical; in 2024, the fertility rate fell to just 1.1 births per woman, far below the replacement rate of 2.0. This permanent population decline will dramatically shrink the military-age cohort and strain the economy. Furthermore, the massive defense expansion, combined with potential consumption tax cuts and energy subsidies, places immense fiscal pressure on the national budget, risking a bond-market backlash.