US and Japan Intervene Together to Halt Yen's Decline Against Dollar

The United States has joined Japan in a coordinated effort to reverse the yen's sustained weakness against the dollar, with the Federal Reserve Bank of New York selling euros to finance the operation. The bilateral intervention, the first of its kind in more than a decade, temporarily lifted the yen to 157 against the dollar, up from just above 163, its lowest level in four decades. Treasury Secretary Scott Bessent indicated the department stands ready to participate in additional joint intervention if needed.

How the Intervention Worked

On Friday, US and Japanese authorities executed a coordinated market operation designed to counteract what Japan's Finance Minister described as excessive volatility and disorderly movements in the currency pair. The most notable aspect of this action was the mechanism: the Federal Reserve Bank of New York sold euros rather than the traditional dollar assets typically used in such operations. This approach surprised market analysts, as coordinated interventions have historically been funded with dollar reserves.

The shift in strategy raised questions among economists about US motivations. Some analysts suggested that selling euros instead of dollars may have been intended to prevent Japan from liquidating US Treasury holdings to finance the intervention independently—a move that could have caused broader market disruption. The yen initially gained approximately 5 percent before paring some of those gains by Monday trading sessions.

Market Skepticism About Durability

Despite the immediate bounce, major financial institutions expressed doubt about the sustainability of the yen's recovery. UBS strategists noted that Japan's underlying policy framework remains unlikely to generate lasting currency strength, with real interest rates still negative. HSBC analysts added that without more aggressive Bank of Japan rate increases and a clearer government stance on currency policy, downward pressure on the yen will persist. The greenback's resilience also reflects uncertainty about whether the Federal Reserve will raise interest rates in September, a factor that continues to attract international demand for US Treasury securities.

Robin Brooks of the Peterson Institute for International Economics suggested that the unconventional intervention approach—using euros rather than dollars—could paradoxically undermine confidence in the yen long-term. Markets typically interpret currency interventions as signals of a currency's fundamental strength; in this case, the unusual funding mechanism may have signaled underlying weakness requiring creative solutions.

The Broader Context

Japan has struggled with yen weakness for decades, a legacy of the 1990s recession and the subsequent policy of maintaining near-zero or negative interest rates through much of the 2010s. While the Bank of Japan raised rates in 2024, the currency has continued to decline, driven partly by higher energy costs linked to geopolitical tensions. President Trump framed the US action as a gesture of support for an allied nation, emphasizing that stronger Japanese currency would benefit the global economy. Treasury officials stressed that the move reflects US commitment to market stability and Japan's economic wellbeing.