The de facto closure of the Strait of Hormuz following recent military action by the U.S. and Israel against Iran has triggered significant disruptions in global energy and commodity markets, with pronounced effects in Japan and across Asia [1][2][3][4][8]. Despite a two-week ceasefire, vessel traffic through the strait remains tightly restricted, and Iran is reportedly planning to charge shipping firms fees in cryptocurrency to allow passage, further complicating the situation [8]. President Donald Trump has warned Iran against imposing such fees, threatening further action if compliance is not met [6][8].
Japan, which relies on the Middle East for nearly 90% of its crude oil imports, faces heightened energy security risks and economic instability. Oil prices have surged, with West Texas Intermediate (WTI) futures rising sharply in late March 2026 and trading at $91.95, up 0.31% on the day [2][6]. Analysts warn that a prolonged closure could push global oil prices well above $150 per barrel, potentially shaving up to 0.3 percentage points off Japan's GDP growth for every $10 increase in crude prices, raising import bills and weakening the yen [2]. To stabilize domestic energy supplies, Japanese Prime Minister Sanae Takaichi announced plans to release approximately 20 days' worth of additional oil reserves starting from early May [5]. Finance Minister Satsuki Katayama, however, downplayed immediate oil shortage risks [5].
The closure has also impacted other commodities. Aluminum prices are near a four-year high, prompting Japanese firms to seek alternative sources such as Australia and Russia, though the transition is expected to be slow and fraught with risks including potential sanctions and logistical challenges [4]. In the plastics sector, Formosa Plastics, a major Taiwanese PVC supplier, has withheld April price announcements due to restricted raw material flows, causing production cuts and price surges across Asia. Spot prices for PVC have climbed by several percentage points compared to the previous month, and market sentiment remains cautious amid ongoing volatility [3].
Surging oil prices have fueled inflation concerns, weighing on gold prices, which declined to near $4,760 as traders await the US CPI inflation report for March. The headline CPI is expected to rise to 3.3% year-on-year, up from 2.4% in February, driven by energy inflation [7]. Market participants are closely monitoring developments in the Middle East, as continued disruptions could further impact commodity prices and global economic stability. Analysts emphasize the urgent need for Japan to expand its domestic energy resilience, accelerate investment in renewables, and reconsider nuclear power to reduce exposure to geopolitical risks [2].
CONCLUSION
The closure of the Strait of Hormuz has led to sharp increases in energy and commodity prices, supply chain disruptions, and heightened economic risks for Japan and Asia. Despite a ceasefire, market volatility persists, prompting government interventions and strategic shifts among Japanese firms. The situation underscores the urgent need for diversification and resilience in energy sourcing as geopolitical tensions continue to threaten global supply chains.