Reading time: 6 min
USD/JPY approached 158. The yen fell for a third consecutive week. Finance Minister Katayama said intervention “remains an option” and that authorities are watching the decline “with a strong sense of urgency.” None of it mattered. The world’s oldest safe-haven currency is being repriced as an energy liability in real time.
The logic is brutal and straightforward. Japan imports roughly 95% of its crude oil from the Middle East, according to S&P Global data covering the first half of 2025 and confirmed by Reuters. Around 70% of those barrels pass through the Strait of Hormuz (Nippon.com, Reuters). When Iran shut the strait, it didn’t just raise Japan’s import bill. It severed the physical supply line that keeps the world’s fourth-largest economy running. The United States, by contrast, is a net energy producer. When oil surges, America’s trade balance improves. Japan’s collapses.
That asymmetry explains why the yen is falling while the dollar is rising, even though both currencies historically attract capital during crises. As Barclays Head of FX Research Themistoklis Fiotakis noted at the start of the month, every 10% rise in oil prices adds roughly 0.5-1% of upside to the dollar (Forextraders.com). The inverse applies to the yen. Every barrel that gets more expensive widens Japan’s trade deficit, increases imported inflation, and undermines the Bank of Japan’s ability to tighten policy. The carry trade, which normally unwinds in a risk-off event and sends the yen higher, has barely flinched.
The Numbers That Matter
Japan holds 254 days of oil reserves, split between government stockpiles covering 146 days, private-sector holdings covering 101 days and joint stockpiles with producing countries covering roughly 7 days, according to Nippon.com and Reuters citing METI data as of December 31, 2025. Officials said this week Japan has no current plans to release those reserves.
Oil is the comfortable part of the story. Gas is the problem. Japan holds roughly 2.19 million tonnes of LNG in utility storage as of March 1, up 10% from the prior week after METI ordered companies to build buffers, according to Reuters. That equals about 12 days of domestic consumption. LNG-fired plants generate between 30% and 40% of Japan’s electricity. Unlike oil, which can sit in tanks for months, LNG has to keep arriving. If all imports were halted simultaneously, Japan’s total stockpile — including non-utility storage — would last roughly three weeks, Kpler analyst Go Katayama told Reuters.
The narrower scenario is less alarming. Only about 6% of Japan’s LNG passes directly through Hormuz and only 11% comes from the Middle East, with Australia supplying 40% of total imports (MarketScreener, Reuters). In a pure Hormuz-only outage, Katayama estimated Japan’s LNG reserves could cover roughly 44 weeks. But markets aren’t pricing the narrow scenario. They’re pricing the risk of a broader disruption — Iranian drone and missile strikes on Gulf energy infrastructure, the Qatar production halt at Ras Laffan, and the possibility that shipping lanes beyond the strait itself become uninsurable. Kansai Electric Power, which sources about 13% of its LNG from Qatar, warned that a prolonged conflict could affect its supplies (Reuters).
The BoJ Is Trapped
Bank of Japan Governor Kazuo Ueda warned this week that the Middle East conflict could materially impact Japan’s economy and signalled a likely prolonged hold on interest rates (TradingEconomics). That is the opposite of what the yen needs. Before the war, markets were positioning for at least one more BoJ rate hike in the first half of 2026. Now the calculus has reversed. Higher energy costs feed directly into imported inflation, but the kind of inflation you get from an oil shock is cost-push, not demand-pull. Raising rates into it would crush domestic consumption without addressing the source of rising prices.
The rate differential with the United States is already punishing. US 10-year Treasury yields sit above 4.1%, while Japanese government bond yields are just over 2.0% (InvestingCube). Fed rate-cut expectations have been pushed back from July to September or October, with money markets now pricing in only about 37 basis points of easing for 2026 (TradingEconomics). If the BoJ freezes and the Fed delays, the yield gap that funds the carry trade stays wide. That keeps pressure on the yen regardless of what happens in the Gulf.
Finance Minister Katayama repeated her intervention warning twice this week and said she is coordinating closely with US Treasury Secretary Scott Bessent (TradingEconomics). In late January, rumours of coordinated US-Japan intervention triggered an 800-pip reversal in USD/JPY. But as TradingNews pointed out, the conditions are fundamentally different now. In January, the dollar was weak and the macro backdrop supported yen strength. In March, the dollar is surging on safe-haven flows, the US is a net beneficiary of the energy crisis, and the Fed’s rate-cut timeline keeps getting pushed further out. The forces driving USD/JPY higher are structural, not speculative. Intervention would be a short-term shock, not a trend reversal.
The Refiners Are Already Moving
At least one major Japanese refiner cancelled March-loading exports of gasoline, jet fuel and diesel this week to prioritise domestic supply, according to DiscoveryAlert citing industry sources. The Japan Times reported that refiners have asked the government to expedite access to strategic petroleum reserves, warning that standard procurement bidding procedures could take weeks. Japan’s three-tier reserve system is sophisticated on paper. In practice, releasing barrels requires bureaucratic processes designed for transparency, not speed.
JERA, Japan’s largest LNG buyer and the government’s agent for emergency procurement, has been instructed by METI to secure at least one LNG cargo of about 70,000 tonnes per month under the Strategic Buffer LNG scheme (Reuters). So far, METI said it has received no requests for emergency SBL usage. But the absence of an immediate shortage is not the same as security. If the conflict extends through March, the buffer shrinks with every week that passes without new cargoes clearing the Gulf.
What the Yen Is Pricing
USD/JPY traded around 157.5 on Friday, on track for its third consecutive weekly decline in the yen (TradingEconomics). The pair is approaching 158, the level that triggered direct intervention warnings and suspected MoF action in late January. InvestingCube noted that the Ministry of Finance typically gets worried in the 157-160 range, with intervention threats intensifying above 158. But there is a difference between intervening to defend the yen against speculative positioning and intervening against a structural energy shock. Speculators can be squeezed. Energy dependence cannot.
The broader FX picture reinforces the pattern. EUR/USD broke below 1.16 for the first time in 2026. GBP/USD crashed to a three-month low near 1.3250. AUD/USD fell through 0.70. The DXY gained more than 1.5% on the week, its best performance in months, driven almost entirely by safe-haven demand and the US energy independence premium (TradingEconomics, Yahoo Finance). Every major currency fell against the dollar. The yen fell the most, because the yen has the most to lose from an energy war centred on the world’s most important chokepoint for Japanese oil and gas.
CNBC, citing UBP research, noted that the Middle East supplies 75% of Japan’s oil imports and 70% of Korea’s, making Northeast Asia the region most exposed to a Hormuz supply shock. The conflict hasn’t just delayed the yen’s recovery. It has exposed the structural fragility that monetary policy alone cannot fix.
Japan runs on imported energy. It generates electricity from imported gas. It fuels its cars with imported oil. It heats its homes with imported LNG. The yen’s safe-haven status was always conditional on those supply lines staying open. This week they didn’t. And the currency market noticed before anyone else.
