亚洲盟友面临的是双重约束：能源暴露与安全依赖。伊朗对霍尔木兹海峡附近航运的威胁，正在扰乱澳大利亚、日本、菲律宾、韩国和泰国的能源供应；与此同时，特朗普于 3 月 14 日要求包括日本和韩国在内的亚洲盟友向海湾派舰。各国担心被卷入遥远战争，但更担心若不响应，美国会减少安全承诺。这使风险不只是能源冲击，也是不对称联盟压力。

已有军事再部署强化了这种焦虑。澳大利亚已派出一架指挥控制飞机和一些空对空导弹；驻日美军的一支海军陆战队远征部队正高速驶向海湾，这是自 2004 年伊拉克战争以来其首次离开太平洋，令亚洲暂时失去一支美军危机反应力量。美国还从韩国调走了 Patriot 拦截弹和 THAAD 系统部件。日本虽拥有可协助扫雷的能力，但民调显示 80% 的日本民众反对这场冲突，限制了直接参与空间。

台湾的脆弱性最具数量特征。2022 年台湾同意购买约 100 枚 PAC-3 MSE，原定于 2025 和 2026 年交付，并另订购 NASAMS 拦截弹和 HIMARS；这些军购许多都服务于 2027 这一关键时间点，即美国官员认为中国军队应已具备攻打或封锁台湾能力的年份。若伊朗战争拖延这些交付，将直接冲击台湾军力规划与公众士气。整体趋势是，随着美国把兵力与导弹防御资产从亚洲抽往中东，亚洲盟友正更认真地思考“Plan B”。

Asian allies face a dual constraint: energy exposure and security dependence. Iran’s threats to shipping near the Strait of Hormuz are disrupting energy supplies to Australia, Japan, the Philippines, South Korea and Thailand; at the same time, Trump on March 14th demanded that Asian allies including Japan and South Korea send ships to the Gulf. Governments fear being drawn into a distant war, but they fear even more that America may reduce security commitments if they do not respond. The risk is therefore not just an energy shock but asymmetric alliance pressure.

Military redeployments have intensified that anxiety. Australia has already sent a command-and-control aircraft and some air-to-air missiles; a US Marine expeditionary unit based in Japan is sailing rapidly to the Gulf, the first time it has left the Pacific since the 2004 Iraq war, temporarily depriving Asia of an American crisis-response force. America has also removed Patriot interceptors and parts of a THAAD system from South Korea. Japan has minesweeping capacity that could help, but polling shows 80% of Japanese oppose the conflict, limiting room for direct participation.

Taiwan’s vulnerability is the most numerically defined. In 2022 Taiwan agreed to buy around 100 PAC-3 MSE missiles, with delivery expected in 2025 and 2026, and also ordered NASAMS interceptors and HIMARS launchers; many of these purchases are meant to strengthen defences by 2027, the year by which American officials believe China’s forces should be ready to attack or blockade Taiwan. If the Iran war delays these deliveries, Taiwan’s military planning and public morale will both suffer. The broader trend is that as America shifts forces and missile-defence assets from Asia to the Middle East, its Asian allies are thinking more seriously about a Plan B.