U.S. and Japan confirm first joint yen intervention since 2011

The United States and Japan confirmed last week they carried out a rare coordinated intervention to prop up the Japanese yen after it slid to 40-year lows, marking the first joint currency market action by the two allies since 2011. The operation drove the yen from near 164 per dollar to around 157, and sent the Bloomberg Dollar Spot Index to its lowest level in a month.

How the Intervention Unfolded

Japan's Finance Minister Satsuki Katayama announced on Monday that Tokyo and Washington had acted together on Friday to counter "excessive volatility and disorderly movements" in the yen. The action followed a massive unilateral intervention by Japan on Thursday, when Tokyo spent approximately ¥8.45 trillion — roughly $53 billion — buying yen in New York markets, according to Bank of Japan data cited by Bloomberg.bbc+2

U.S. Treasury Secretary Scott Bessent confirmed Friday's coordinated effort, writing that "Friday's coordinated foreign exchange actions countered disorderly yen movements" and that the Treasury "will not hesitate to participate in further joint intervention". A Reuters photograph captured a handwritten note in front of Bessent at a Friday cabinet meeting reading "To Do: Buy Japanese Yen (JPY) $5-10 bil".cnbc+3

The intervention followed months of preparation, according to Reuters, which reported that a rare public alignment of interests between Washington and Tokyo on exchange rates made the joint action possible. President Donald Trump confirmed U.S. participation, framing it as a gesture of support for Japan and global economic stability.nytimes+2

What Drove the Yen to Crisis Levels

The yen's prolonged weakness stemmed from the wide interest rate differential between the United States and Japan. With the Bank of Japan maintaining a policy rate of 1% while the Federal Reserve kept rates elevated, the yen remained an attractive funding currency for carry trades. ING analysts estimated that the depreciation had pushed Japanese import prices up roughly 30% year-over-year.bloomberglinea

UBS ↘ 1.90% strategists Teck Leng Tan and Dominic Schnider noted that "despite the latest intervention, the yen remains vulnerable to renewed weakness while markets perceive the Bank of Japan is still behind the curve". The firm projects USD/JPY at 162 in September, 160 in December, and 158 by mid-2027.bloomberglinea

Implications for Global Markets

The dollar weakness extended beyond the yen. Latin American currencies showed a mixed response, with the Chilean peso, Brazilian real, and Mexican peso gaining ground while the Colombian and Argentine pesos retreated. Goldman Sachs ↘ 1.43% maintained that the Brazilian real and Colombian peso continue to offer the most attractive carry trade propositions among major emerging-market currencies.noticiasdebariloche+1

Analysts cautioned that the intervention's durability depends less on the volume of purchases and more on U.S. economic data and Federal Reserve policy. ING's Chris Turner and Michiel Tukker said "the success of this latest intervention effort will depend less on how many yen the authorities buy and more on whether U.S. economic data softens enough to avert further tightening by the Federal Reserve".bloomberglinea