Iran's de facto blockade of the Strait of Hormuz has sent shockwaves through Japanese government bond markets. By early April 2026, Japan's 10-year benchmark yield surged to 2.39%, its highest level since 1999, surpassing the 2008 financial crisis peak by roughly 30 basis points. The 5-year yield climbed to 1.72%, approaching its own record territory.
Energy Lifeline Cut: 95.9% of Japan's Crude Imports Depend on Hormuz
Iran imposed the blockade in late February and early March 2026 following U.S. and Israeli military operations. Tanker flows through the strait fell below 10% of normal levels. Japan's fiscal 2024 crude imports relied on the Middle East for 95.9%, with the UAE at 43.6%, Saudi Arabia at 40.1%, Kuwait at 6.4%, and Qatar at 4.1% — all passing through Hormuz. Brent crude spiked above $113-$116 per barrel, with physical Dubai crude hitting $170 at points. The International Energy Agency coordinated emergency reserve releases to cushion the blow.
Tokyo moved swiftly. On March 9, 2026, the Ministry of Economy, Trade and Industry instructed ten domestic storage bases to prepare state reserve releases. Japan committed roughly 80 million barrels (about 45 days of supply) — the largest drawdown in its history. Officials and analysts view this as temporary relief, not a solution.
BOJ's Rate Hike Dilemma: Inflation vs Growth
Energy costs have fed directly into consumer prices. A weaker yen, trading near 160 against the dollar, has amplified import costs. The Bank of Japan (BOJ) kept its short-term rate at 0.75% at its last meeting but maintains a tightening bias. Governor Kazuo Ueda has signaled further hikes remain on the table if underlying inflation trends toward the 2% target. Markets now price in a 60-70% probability of a rate hike at the BOJ's April 27-28 meeting. Goldman Sachs sees July as a more likely timeline, depending on Middle East developments.
The BOJ faces a blunt trade-off: energy-driven inflation is rising, while higher costs risk slowing the broader economy. Major life insurers are sitting on roughly $60 billion in unrealized losses on Japanese government bond holdings.
Yen Carry Trade Unwind: A $500 Billion Time Bomb
Higher JGB yields threaten to unwind an estimated $500 billion in yen-funded carry trade positions across equities, emerging market debt, and crypto. Japan holds $1.225 trillion in U.S. Treasuries (as of January 2026), making it the largest foreign holder. Rising domestic yields reduce appetite for foreign bonds, putting upward pressure on U.S. borrowing costs.
A BOJ rate hike in mid-2024 triggered significant liquidations. A repeat, with the Hormuz blockade still in place, could hit harder. Japan has not invoked the Armed Attack Situation Act to deploy its navy in the strait. The government has joined a U.K.-led coalition of more than 30 countries calling for free passage. President Trump has signaled the conflict could wind down in weeks but also left room for escalation. No resolution was in sight as of this weekend.