Iran granted permission for a Japanese shuttle tanker to transit the Strait of Hormuz amid intensifying regional shipping attacks [2].

The move comes as Japan faces significant threats to its crude-oil supply due to a de-facto closure of the strategic waterway. The passage of the Idemitsu Maru, operated by Idemitsu Kōsan, marks the first time a Japanese-flagged vessel has successfully navigated the strait since the current wave of attacks began [2].

Regional instability escalated following U.S.-Israeli military actions against Iran that began on Feb. 28, 2026 [1]. These "decapitation" strikes prompted Iran to retaliate by targeting shipping lanes, using the closure of the Hormuz strait as strategic leverage [1, 3]. The resulting volatility has impacted global energy markets, with Brent crude oil rising approximately 60% on a monthly basis [5].

Iranian officials said the permission granted to the Idemitsu vessel was a diplomatic gesture of friendship [2]. This gesture is reportedly linked to historic events dating back to 1953 [3].

Despite this single passage, the long-term security of Japan's energy imports remains uncertain. Some reports suggest that if the conflict between the U.S. and Iran continues, Japan could potentially receive no crude oil at all [3]. Others point to the Idemitsu transit as evidence that limited oil flow is still possible through diplomatic channels [2].

The Strait of Hormuz, located between Iran and Oman, remains a critical chokepoint for global oil transit. The continued tension between Iran, the U.S., and Israel has turned the waterway into a primary theater of economic and military pressure [1, 4].

“The Idemitsu Maru marks the first time a Japanese-flagged vessel has successfully navigated the strait since the current wave of attacks began.”

The selective permission granted to a Japanese vessel suggests that Iran is using the Strait of Hormuz not only as a military tool but as a diplomatic instrument. By allowing specific shipments, Tehran can signal a willingness to maintain ties with non-combatant nations like Japan while simultaneously pressuring the U.S. and Israel through the threat of a total energy blockade.