Yen intervention risks failure as Iran war clouds Japan's currency defence

Japan's suspected JPY5-6 trillion yen intervention may prove its least successful yet as the Iran war leaves authorities at the mercy of unpredictable geopolitical factors, MUFG warns. Summary: Japanese authorities are suspected to have intervened in foreign exchange markets as dollar-yen fell from near 160 to below 157, with market estimates based on Bank of Japan current account data pointing to operations of around JPY5-6 trillion, or roughly $32-38 billion, according to MUFG MUFG warned the latest intervention could prove the least successful of any previous episode, citing Japan's heightened exposure to unpredictable geopolitical factors stemming from the Iran conflict, per the bank's note The intervention in scale mirrors operations conducted in April 2024 and October 2022, but MUFG cautioned that a sustainable move lower in dollar-yen would ultimately depend on Federal Reserve policy direction and Bank of Japan rate hikes, according to the same note MUFG's base case calls for two Bank of Japan rate hikes in June and December this year, alongside de-escalation in the Strait of Hormuz, as the conditions needed for a gradual move toward 152 in dollar-yen, per the bank's analysis Current optimism around a possible U.S.-Iran peace deal could evaporate quickly, leaving Japanese authorities more exposed to sudden reversals than in previous intervention cycles, according to MUFG U.S. Treasury Secretary Scott Bessent is separately scheduled to visit Tokyo next week, where currency issues including yen weakness are expected to feature in bilateral discussions with the prime minister, finance minister and Bank of Japan governor, per Nikkei reporting Japan's suspected intervention to support the yen may turn out to be its least effective yet, according to analysis from MUFG, which warns that the Iran conflict has left authorities more exposed to sudden geopolitical shifts than at any point in previous rounds of currency defence.

Dollar-yen dropped sharply from levels near 160 to below 157 in recent sessions, a move that market participants attributed in large part to suspected official intervention. Estimates derived from Bank of Japan current account deposit data and shifts in money market positions pointed to operations in the region of JPY5-6 trillion, equivalent to roughly $32-38 billion. That scale places the suspected action in the same bracket as interventions carried out in April 2024 and October 2022, both of which provided temporary relief without delivering a durable reversal in the exchange rate.

MUFG's concern is that this time the environment is even less forgiving. In previous intervention episodes, the primary variable was the Federal Reserve's policy trajectory, a factor that, while uncertain, is at least driven by observable economic data and central bank communication. Now, the trajectory of the Iran conflict has become an equally important determinant, and one that is far harder to model or anticipate.

The current mood in markets leans toward optimism about a potential U.S.-Iran peace deal, but MUFG cautioned that such sentiment can shift abruptly, exposing the yen to renewed selling pressure at short notice. For a sustainable decline in dollar-yen, MUFG argues that intervention alone is insufficient. The fundamentals need to cooperate, meaning a Fed that turns more accommodative and a Bank of Japan that follows through on rate increases.

The bank's base case pencils in two BOJ hikes, in June and December of this year, which in combination with de-escalation in the Strait of Hormuz would underpin a gradual drift toward 152 in dollar-yen. That remains the central scenario, but the confidence around it is lower than in previous cycles given the geopolitical overlay. The pressure on Japanese authorities comes at a diplomatically sensitive moment.

U.S. Treasury Secretary Scott Bessent is due in Tokyo next week for a series of bilateral meetings that will include yen weakness on the agenda alongside economic security topics such as rare earths and energy procurement. Bessent is scheduled to meet individually with Prime Minister Sanae Takaichi, Finance Minister Satsuki Katayama, and Bank of Japan Governor Kazuo Ueda.

Any signal from those discussions of a coordinated or at least acknowledged approach to currency levels could provide a supplementary line of defence for the yen beyond what intervention and rate expectations alone can deliver. The broader context is one in which Japan's structural yen weakness is being compounded by the same energy price surge that is driving inflation concerns globally. Higher oil costs inflate Japan's import bill directly, widening the current account pressures that have weighed on the currency over recent years.

Intervention can smooth volatility, but it cannot resolve those underlying dynamics, which is precisely what makes the current episode, in MUFG's view, the most challenging that Japanese authorities have yet faced. --- The scale of the suspected intervention, estimated at JPY5-6 trillion, is comparable to previous operations that ultimately proved temporary without supportive fundamentals, raising the risk that the yen remains vulnerable once the initial market impact fades. With the Fed showing no imminent signs of a dovish pivot and the Iran conflict injecting unpredictable volatility into energy prices and risk sentiment, the two pillars underpinning MUFG's 152 target look fragile in the near term. Oil price moves tied to the Iran situation have a direct bearing on Japan's import bill, which itself feeds into the yen's structural weakness, creating a feedback loop that intervention alone cannot break.

This article was written by Eamonn Sheridan at investinglive.com.