- The yen surged more than 2% against the dollar Thursday in a move traders and analysts called a likely government intervention, after officials warned their patience with yen weakness had “run out.”
- Japan imports nearly all of its energy, with 90% of crude oil transiting the Strait of Hormuz — making the indefinite closure a direct, severe economic threat to the country.
- Oil prices are up roughly 80% since the start of the year; Finance Minister Satsuki Katayama called for “decisive action” and top currency diplomat Atsushi Mimura issued “the final evacuation warning.”
- The dollar had reached ~160 yen — a level that has historically triggered Japanese intervention — before the sharp reversal; analysts warn the relief may be short-lived as long as Hormuz remains closed.
What Happened?
The Japanese yen surged sharply against the dollar Thursday after Japan’s Finance Minister Satsuki Katayama warned it was time for “decisive action,” and top currency official Atsushi Mimura issued what he called “the final evacuation warning” to traders. Although Japanese officials typically decline to confirm interventions, the more-than-2% single-day move — from near 160 yen per dollar to the low 157s — bore all the hallmarks of direct market intervention, according to traders and analysts. The yen had been under severe pressure from the Iran war’s oil shock, the Bank of Japan’s slow pace of rate increases, and Prime Minister Sanae Takaichi’s expansionary fiscal policies. The dollar has gained roughly 15% against the yen over the past three years.
Why It Matters?
Japan’s vulnerability to the Iran war is uniquely acute. The country imports nearly all of its energy — and 90% of its crude oil transits the Strait of Hormuz. A prolonged closure drives up Japan’s import bill, accelerates domestic inflation, and weighs on economic growth simultaneously — a toxic combination for the yen. With oil prices up approximately 80% since the start of 2026, Japan is absorbing one of the largest terms-of-trade shocks among developed economies. Currency intervention can buy time, but analysts note it cannot address the underlying driver: as long as the Strait of Hormuz remains closed and oil prices stay elevated, the economic forces pressing the yen weaker will persist.
What’s Next?
The Bank of Japan held rates steady in April in a split vote that signaled a possible June hike. Many economists expect the BOJ to raise borrowing costs at its June meeting, which could provide some fundamental support for the yen by narrowing the interest rate differential with the U.S. But with the Fed also on hold amid its own inflation challenges from the Iran energy shock, the rate differential is unlikely to close quickly. If Trump proceeds with fresh military action in Iran — as CENTCOM briefed the president Thursday — another oil spike would immediately renew pressure on the yen, potentially forcing another round of costly intervention.
Source: The Wall Street Journal
