US, Japan intervene jointly to lift yen from 40-year low

The United States and Japan carried out a coordinated currency intervention last week to arrest a steep decline in the yen, marking the first such joint action since 2011. The move helped lift the currency to its strongest level in three months, reaching around 155 to 157 yen per dollar on Monday after it had fallen to nearly 164, a four-decade low.

Japanese officials confirmed that Tokyo sold dollars to purchase yen, with Bank of Japan data pointing to roughly 36 to 59 billion dollars spent in recent operations, including activity in New York markets. US Treasury Secretary Scott Bessent signaled Washington's readiness to act again, noting in a cabinet meeting that purchases of 5 to 10 billion dollars worth of yen were under consideration. Both governments stated they would not hesitate to repeat the effort if needed.

The yen's weakness stems primarily from Japan's persistently low interest rates compared with those in the United States and other major economies. This gap encouraged carry trades in which investors borrowed cheaply in yen to invest in higher-yielding assets elsewhere. Recent political developments in Japan added pressure, as Prime Minister Sanae Takaichi has advocated tax and spending measures to stimulate growth while voicing concerns about higher rates from the Bank of Japan. Those policies have also contributed to rising Japanese government borrowing costs, raising worries about spillover effects on global markets, including potential increases in US debt servicing expenses.

President Donald Trump described the intervention as a response to Japan's request for assistance, emphasizing longstanding alliance ties. The action aligns with broader efforts to maintain stability amid volatile currency flows that can amplify economic shocks. Historical precedent shows coordinated interventions remain infrequent, with the last instance occurring after the 2011 earthquake and tsunami in Japan to manage post-disaster volatility.

Market analysts offered cautious assessments of the intervention's durability. Strategists at UBS noted that Japan's policy mix, including gradual Bank of Japan normalization and still-negative real rates, makes sustained yen appreciation unlikely without deeper structural shifts. HSBC echoed that faster rate increases from the Japanese central bank would be necessary for lasting strength, as repeated interventions alone may only deter speculators temporarily through a sense of vigilance rather than fundamental change. ING observed that the dollar showed limited reaction, partly because questions persist over Federal Reserve policy moves.

The episode underscores the interconnected nature of advanced economies, where currency movements in one major market can influence borrowing costs and investment flows worldwide. Officials in both countries framed the step as a low-cost measure with potential benefits for broader financial stability, though its effectiveness will depend on follow-through and evolving monetary conditions in Tokyo.