Washington joins Tokyo in buying yen, pulling the currency back from a four-decade low

Japan and the United States bought yen together after the currency weakened past 163 to the dollar. The operation lifted the yen to about 157, and both governments have confirmed it. Japan's finance minister, Satsuki Katayama, and Scott Bessent, the United States Treasury secretary, publicly acknowledged the coordinated action, a joint yen purchase of a kind the two governments have not carried out together in many years.

Bessent wrote that Washington "will not hesitate to participate in further joint intervention." He also said the Treasury supports expanding a standing arrangement that lets foreign central banks borrow dollars against their holdings of United States government debt (the Federal Reserve's Foreign and International Monetary Authorities repo facility). The Financial Times describes the move as a new phase of American currency activism, in which the Treasury is willing to disrupt trading positions that run against its own interests. The Japan Times reports that analysts see several American objectives at stake, including leverage over trade terms with Tokyo and pressure on the Bank of Japan to raise rates faster.

The mechanism of the operation is unusual. Reports say the New York Federal Reserve funded its yen purchases by selling euros rather than dollars, an arrangement that avoids draining dollar liquidity while still buying yen. Commentators in Tokyo and New York have questioned both the method and the motive. Some argue that the deeper worry is Japan becoming a forced seller of United States Treasuries if the yen keeps falling and Japanese institutions bring capital home.

Intervention delays the pressure. It does not close the gap that produced the slide, which is the distance between a Bank of Japan policy rate still far below American rates and a Japanese government still issuing large volumes of debt. Every previous round of official currency buying in the region has faced the same arithmetic. As long as the interest-rate differential and the fiscal path stay where they are, traders will push the yen back toward that level, and each attempt raises the cost of the next defense.