This article examines the domestic political dynamics behind US president Donald Trump’s “America First” approach to trade and foreign policy, to understand better how long this strain of American economic nationalism might last and what it means for Japan’s national security strategy. The political base for Trump’s trade protectionism and apparent indifference to allies has roots stretching back into American history, but this movement has strengthened in recent years due to a combination of growing economic inequality in the United States, demographic changes, and the impact of fast-paced technology development and economic globalization. These political trends are likely to persist beyond Trump’s presidency, although some potential negative effects on Japan and the US-Japan alliance in the medium-to-longer term can be mitigated by Japan’s proactive foreign policy and other steps. The alliance still offers a great deal of value to both countries—now and into the future—but Japan should consider a slightly larger global leadership role in concert with others, even as the allies work to enhance their continued cooperation on shared interests.

中文翻译：

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美国的政治变革及其对美日同盟的启示

本文研究了美国总统唐纳德·特朗普（Donald Trump）对贸易和外交政策采取“美国优先”方法的背后的国内政治动态，以更好地理解这种美国经济民族主义的影响能持续多久，以及对日本的国家安全战略意味着什么。特朗普贸易保护主义和对盟友的明显冷漠的政治基础可以追溯到美国历史，但由于美国经济不平等加剧，人口变化以及快速移民的影响，近年来，这种运动得到了加强。加快技术发展和经济全球化的步伐。这些政治趋势可能会持续到特朗普担任总统以外的时间，尽管日本的积极外交政策和其他措施可以减轻中长期对日本和美日同盟的潜在负面影响。该联盟现在和将来都为两国都提供了巨大的价值，但是日本应该考虑与其他国家一起发挥更大的全球领导作用，即使盟国致力于增进两国在共同利益上的持续合作。