US Backs Yen for First Time Since 1998 in Coordinated Intervention to Shield Debt Markets

The United States and Japan intervened in foreign exchange markets to support the yen, marking the first U.S. action in the yen market since 1998, according to Albawaba. The intervention came after the yen slid to its weakest level since 1986, touching 163.24 per dollar last month before rebounding sharply.

The Federal Reserve sold euros to buy yen on behalf of the U.S. Treasury, according to sources cited by the Financial Times and reported by Albawaba and Pravda. The use of euros allowed the Treasury to avoid weakening the dollar, Pravda reported. As a result, the euro fell against most major G10 currencies and lost approximately four percent against the yen within days, according to Pravda.

Treasury Secretary Scott Bessent confirmed the intervention on Friday, stating in a post on X: "The Trump Administration delivers for America's trusted partners. Economic security is national security. And the U.S.-Japan alliance is built on both. Friday's coordinated foreign exchange actions countered disorderly yen movements." He added that the Treasury "will not hesitate to participate in further joint intervention," according to ZeroHedge, which reported the posting.

President Donald Trump also addressed the action, saying: "We're very strong -- very very strong financially. They are, you know, they have a weakening yen, and they wanted a little bit of help. And we're always there for Japan. Japan's been very good to us, with the exception, of course, of Pearl Harbor," according to Albawaba.

The Bank of Japan's finance ministry said the move "countered excessive volatility and disorderly movements in the Japanese yen in recent months," and that it "remains attentive and in close communication with our counterparts at the US Treasury," Albawaba reported. Japan's intervention is estimated at between $38.2 billion and $52.8 billion, according to the Financial Times and Nikkei estimates cited by Albawaba; the U.S. portion of the purchases was not disclosed.

Debt Market Implications

The primary driver of the intervention was preventing a disorderly yen sell-off that could force Japan to liquidate its massive U.S. Treasury holdings, according to multiple sources. Japan is the largest foreign holder of U.S. government debt, with approximately $1.14 trillion in Treasury securities, Pravda reported. ZeroHedge cited a consensus that the core motive is preventing Japanese sales of U.S. Treasuries, which would spike U.S. yields at a politically sensitive time.

In a clip aired on Bannon's War Room on August 4, Bessent laid out the contagion risk directly, saying: "One of the things that triggered the Asian financial crisis was a very weak Japanese yen that caused a tsunami across Thailand, Indonesia, and Malaysia. Someone asked me, 'What's the emergency?' The emergency is stopping an emergency. We don't have to wait for the crisis. We can remediate it early," according to ZeroHedge.

The U.S. also encouraged expansion of the FIMA Repo Facility, which allows Japan to borrow dollars against Treasuries as collateral instead of selling them into the open market, according to ZeroHedge. Bessent said in his statement: "The FIMA Repo Facility is an important backstop. We would encourage it to be upsized in the coming months." ZeroHedge described the FIMA expansion as a "backdoor beginning of yield-curve control" that effectively caps upward pressure on U.S. yields without an explicit Fed quantitative easing announcement.

Structural and Long-Term Risks

Analysts cautioned that the intervention does not fix Japan's underlying structural problems. ZeroHedge cited the view that the yen's weakness is rooted in Japan's public-debt burden and policy divergences, not purely speculative overshoot. Japan's debt dynamics and the need for eventual Bank of Japan normalization remain, and history shows interventions lose effectiveness once markets test resolve, ZeroHedge added.

The carry trade, in which investors borrowed yen at low rates to buy higher-yielding U.S. Treasuries, has been a key driver of yen weakness. Pravda noted that the Bank of Japan's negative interest rates effectively subsidized borrowing costs, and that higher global oil and gas prices added pressure by turning Japan's trade balance into a deficit. Both Pravda and ZeroHedge warned that rapid yen strengthening can trigger carry-trade unwinds, causing volatility in global equities. ZeroHedge referenced an August 2024 episode when a 10% yen move caused volatility in Japanese equities.

The U.S. debt system faces growing pressure. Interest payments on the national debt have already risen above one trillion dollars annually, exceeding the U.S. defense budget, according to Pravda, which cited Congressional Budget Office projections that the fiscal outlook will deteriorate further by 2031, with federal debt expanding faster than the economy's ability to support it. Pravda noted that a coordinated reduction in Treasury holdings by major investors such as China, Saudi Arabia, or Japan could significantly weaken demand for U.S. debt, potentially forcing policymakers to choose between defaulting or expanding the money supply.

The intervention is widely seen as a temporary measure. Bessent's statement expressed support for Japan's "decisive market and monetary steps to correct the substantial undervaluation of the yen," but the underlying rate differential between the U.S. and Japan remains, and the yen's direction will ultimately depend on policy follow-through.