The US Treasury intervened to support Japan's weakened yen—the first such action in nearly four decades—as Japan holds over $1.1 trillion in US Treasury bonds. The move serves US self-interest: a major yen crisis could force Japan to sell US bonds, raising borrowing costs for Washington and destabilizing global bond markets. Treasury Secretary Bessent framed it as "a signal of friendship," but analysts see the transactional nature of Trump-era foreign policy, with implications for regional currency stability in Asia.