Satsuki Katayama, Japan's finance minister, speaks to members of the media in Tokyo, Japan, on Monday, Aug. 3, 2026. Japan confirmed its first joint intervention with the US in currency markets in 15 years and warned that it was ready to act again, after the yen last week slid to a four-decade low. Japan, having intervened to prop its weakening currency to little effect in the past, roped in the U.S. to stage a coordinated intervention last week. The latest fast and furious intervention to prevent Tokyo's currency from drifting involved Washington, giving speculators reason to pause. "Japan's policy mix remains unlikely to generate sustained yen strength," wrote UBS strategists Teck Leng Tan and Dominic Schnider.