Bank of Japan Trapped Between Oil Shocks and Debt Burdens
Iran conflict forces Tokyo into impossible trade-off: tolerate imported inflation or choke growth with rate hikes as fiscal room vanishes.
Oil surging past $100 per barrel has handed the Bank of Japan an impossible choice: absorb a fresh wave of imported inflation or accelerate rate hikes that risk tipping a fragile economy into recession, all while debt service costs climb to multi-decade highs.
Brent crude spiked from around $70 to over $110 per barrel within days after the US-Israeli strikes on Iran triggered the effective closure of the Strait of Hormuz. Japan relies on the Middle East for around 95% of its oil supplies, with around 70% coming via the Strait of Hormuz, which remains impassable as Iranian forces and tanker insurers refuse passage. Japan also depends on the region for about 11% of its LNG imports, with 6% shipped via the Strait, compounding the Energy security crisis.
The timing compounds a structural headache. The Bank of Japan lifted rates to 0.75% in December, a 30-year high, attempting to normalize policy after decades of stimulus. The IMF expects two more hikes this year and another in 2027, targeting a gradual shift toward neutral rates estimated between 1% and 1.5%. Yet headline Inflation fell to 1.5% in January, ending a 45-month run above the BoJ’s 2% target—the first sub-target reading since March 2022.
That reprieve now looks temporary. BoJ board member Hajime Takata warned in February that Japan faces greater-than-expected upswings in prices if overseas factors pushing up prices emerge. Energy prices drive that risk. LNG prices in Japan could surge by around 170% in the event of prolonged closure, according to the Oxford Institute for Energy Studies.
The Fiscal Constraint
Japan enters this crisis with less room to maneuver than in 2022. The fiscal 2026 budget approved in December totals ¥122.3 trillion, a 6.2% year-on-year increase and the first to exceed ¥120 trillion. Debt service costs jumped 10.8% to ¥31.3 trillion, the first time surpassing ¥30 trillion, driven by the end of zero interest rates. Japan’s gross debt reached 234.9% of GDP at end-March 2025, according to the Ministry of Finance—the highest ratio among developed nations.
Rising rates are now a fiscal liability. Japan enters 2026 under economic pressure from inflation, a weak yen, and a growing debt burden, with interest rates at a 30-year high, noted Eurasia Group. Every 25-basis-point hike lifts future debt service obligations on ¥1.2 quadrillion in outstanding bonds. The BoJ holds roughly 46% of government debt, insulating markets from immediate volatility, but unwinding that position over time will test yields.
The yen fell for four straight weeks as the Iran war and surging oil prices weighed on Japan’s oil-importing economy. BoJ Governor Kazuo Ueda warned that a weak yen could intensify imported inflation amid rising oil prices, potentially prompting the central bank to accelerate policy normalization. The USD/JPY exchange rate fell to 159.57 on March 16, hovering near levels that previously triggered intervention warnings. Finance Minister Satsuki Katayama said the government is monitoring currency movements closely and is prepared to act with strong measures if needed.
In 2022, Japan responded to Ukraine-driven energy shocks with ¥25 trillion in fiscal support for electricity and gasoline subsidies. That option is now constrained: debt service has doubled since then, and the BoJ is tightening rather than easing. Unlike 2022, when policy rates were negative, today’s 0.75% baseline means tightening bites harder on leveraged households and corporates.
Wages Trail Inflation Rebound
Real wages increased 1.4% from a year earlier in January, the fastest increase since May 2021, exceeding economists’ median forecast of 0.9%, reported The Japan Times. Nominal wages rose 3% from the previous year, also beating analysts’ expectations. Yet most firms expect to raise wages in fiscal 2026 at about the same rates as in fiscal 2025, per a BoJ survey, not accelerate them. Some manufacturing firms, including motor vehicle-related manufacturers, commented that it would be difficult to continue with high wage growth, mainly owing to a profit decline stemming from US tariff hikes.
If energy costs push inflation back above 2.5%, real wage gains vanish. Core consumer prices rose 2% year-on-year in January, cooling from 2.4% in December and marking the weakest pace of growth in two years. That moderation relied on government energy subsidies and stabilizing food costs. A sustained oil shock reverses both.
All 51 economists surveyed by Bloomberg expect the BoJ to keep borrowing costs unchanged at 0.75% at the end of a two-day meeting on March 20, with the share expecting a move in April jumping to 37% from 17% in the previous survey. ING expects the BoJ’s next rate hike to emerge in October 2026, though if the yen weakens against the USD and continues to drive up import prices, the timeline could be moved forward to Q2.
- Hike rates → Strengthens yen, contains import inflation, but raises debt service costs and risks recession
- Hold rates → Preserves fiscal breathing room, but tolerates 3%+ inflation and yen weakness
- Ease policy → Not credible after two years of normalization; would collapse confidence in inflation targeting
Carry-Trade Risks Mount
The yen’s weakness has sustained one of the world’s largest funding trades. Tohru Sasaki, chief strategist at Fukuoka Financial Group, sees the dollar-yen pair reaching 165 by end-2026, noting that the BoJ isn’t hiking rates aggressively and real interest rates remain deeply negative. Strategists at JPMorgan, BNP Paribas and other firms see the yen weakening to 160 per dollar or beyond by end-2026, driven by still-wide US-Japan yield gaps, negative real rates and persistent capital outflows, reported Yahoo Finance.
But the carry trade remains a two-way risk. Sharp yen swings in 2024-25, including BoJ intervention, make leveraged positions dangerous, as when volatility spikes, traders unwind positions, causing the yen to strengthen further in a self-reinforcing loop. August 2024 provided a preview: yen appreciation triggered by BoJ tightening forced the unwinding of dollar-funded equity positions, with analysts noting that the yen appreciated approximately 25% against the US dollar over six months during the 2008-09 crisis.
The narrowing of the interest rate spread between Japanese bonds and US bonds could lead to an unwinding of the Japanese carry trade and repatriation of capital to Japan, a process that could be reinforced by a meaningful appreciation of the Japanese yen, currently estimated to be undervalued by between 15 and 20 percent, cautioned the American Enterprise Institute. If the Fed cuts more than expected while the BoJ tightens, the differential compresses faster, triggering deleveraging.
What to Watch
BoJ March 20 decision and Ueda press conference tone: Any signal of an April hike would amplify yen strength and unwind pressure. Dovish guidance extends the inflation tolerance window.
Strait of Hormuz reopening timeline: Qatari Energy Minister Saad al-Kaabi said last week it could take months to return to normal deliveries. A protracted closure sustains triple-digit oil prices and eliminates the case for policy patience.
USD/JPY 160 threshold: It’s extremely probable that the Japanese government would intervene in FX markets to defend the yen if it were to depreciate beyond the 158-160 zone, per Investing.com. A break above 160 forces Tokyo’s hand, draining reserves or triggering coordinated G7 action.
Spring wage negotiations (Shunto) outcomes in April: If Japanese businesses pledge pay increases of around 5% for the third year running in 2026, the BoJ would be emboldened to stick to its plans to gradually normalize policy. Wage acceleration above 5% gives the BoJ cover to hike despite energy headwinds; outcomes below 4% lock in dovish bias.
IEA reserve release effectiveness: The International Energy Agency announced that its 32 member countries agreed to release 400 million barrels of oil from emergency reserves. Japan said it would release about 80 million barrels from private and national oil reserves. If reserves stabilize prices below $90 by May, the BoJ gains breathing room. Sustained triple-digit prices eliminate that buffer.