The strength of these alliances depends on whether Trump views Tokyo and Seoul as bulwarks against China’s rise or vassals that can be extorted for financial gain.

President Trump's reciprocal tariffs on Japan (24%) and South Korea (25%) were largely in line with market expectations.

China, Japan and South Korea agreed to jointly respond to U.S. tariffs, a social media account affiliated with Chinese state media said on Monday, an assertion Seoul called "somewhat exaggerated", while Tokyo said there was no such discussion.