The US Bails Out Japan Financial Markets

In an extraordinarily rare move, the United States joined Japan in intervening directly in foreign exchange markets to support the Japanese yen. It was the first joint U.S.-Japan currency intervention to strengthen the yen in nearly three decades.

For months, the Japanese yen had been in freefall, falling to roughly ¥164 per U.S. dollar, its weakest level in about 40 years. The decline was driven primarily by the large gap between U.S. and Japanese interest rates. Investors could borrow cheaply in yen and invest in higher-yielding U.S. assets, a strategy known as the “carry trade,” which put even more downward pressure on Japan’s currency.

Normally, Japan would intervene by itself. The Japanese Ministry of Finance sells dollars from its foreign exchange reserves and buys yen in an effort to increase demand for its own currency. Japan had already spent tens of billions of dollars doing exactly that earlier this year, but those efforts only provided temporary relief.

This time, however, the United States decided that the yen’s collapse had become a broader financial stability issue.

According to Treasury Secretary Scott Bessent, Washington concluded that an excessively weak yen threatened global currency markets and could create ripple effects throughout the international financial system. “The yen’s substantial undervaluation could trigger other economic problems or competitive devaluations of other currencies,” Bessent said.

The United States therefore joined Japan in a coordinated intervention and indicated it was prepared to provide additional support if necessary.

The mechanics are interesting because the United States reportedly did not simply sell dollars for yen. Instead, reporting indicates the Treasury used the Exchange Stabilization Fund to sell euros while the Federal Reserve provided dollar liquidity through existing facilities available to Japan. The goal was to help Japan stabilize the yen without forcing Tokyo to dump large amounts of its U.S. Treasury holdings into the market, which could have pushed American interest rates even higher.

That last point may have been one of Washington’s biggest motivations.

Japan is the largest foreign holder of U.S. Treasury securities. If Japanese authorities had needed to liquidate significant amounts of those holdings to defend the yen, Treasury prices could have fallen and U.S. borrowing costs could have risen further at a time when the federal government is already financing large deficits. By assisting Japan directly, the United States may have been protecting its own bond market as much as Japan’s currency.

The intervention initially appeared successful. The yen strengthened sharply, moving from above ¥163 per dollar to roughly ¥155 in just a few trading sessions after the coordinated action was confirmed publicly.

Currency intervention can change market psychology for days or weeks, but unless the underlying economic forces change, those gains often fade. In this case, the fundamental issue remains the interest rate gap between the Federal Reserve and the Bank of Japan. As long as U.S. rates remain substantially higher than Japanese rates, investors still have a strong incentive to borrow yen and buy higher-yielding assets elsewhere.

The episode is also notable because it represents a departure from the way major currency interventions have typically been handled. Historically, these operations were coordinated through the G7 and involved close consultation among the United States, Europe, and Japan. This intervention was largely bilateral, with Europe reportedly caught off guard, leading some analysts to argue that it reflects a broader shift away from multilateral coordination toward country-to-country financial agreements.