Tanker traffic through Hormuz drops as Iran-U.S. tensions rise

Tanker traffic through the Strait of Hormuz declined sharply this week after Iran attacked three commercial ships, according to data from trade-intelligence firm Kpler. Only 13 tankers crossed on Wednesday, compared with an average of 33 per day in the preceding week. Some vessels followed routes under Iranian control, while others turned off transponders to avoid detection.

Oil prices have risen more than 6% amid concerns that crude exports via the strait could fall as the United States and Iran contest control of the waterway. President Donald Trump said the cease-fire with Iran ended following the attacks, and the United States responded with two rounds of airstrikes and reinstated oil sanctions.

"The collapse of the cease-fire framework, the re-imposition of Iranian oil sanctions, and the scale of U.S. kinetic action inside Iran represent the most significant escalation of the conflict since its opening phase," maritime-intelligence firm Windward wrote in a client note.

Analysts say the market is not assuming a full closure of the strait. Andy Lipow, president of Lipow Oil Associates, noted that pricing appears to reflect a new normal where brief conflict periods alternate with relative calm that still allows tanker transits.

After a June 17 memorandum of understanding between the United States and Iran to reopen the strait, Tehran pledged safe passage and waived tolls for 60 days. However, Iran has required ships to use a northern route under its control and has targeted vessels on a southern route protected by the U.S. Navy.

"This is part of a sporadic targeted campaign by Iran to destabilize the southern corridor and send a message to Gulf State producers that are not sending their oil via that northern corridor," said Michelle Wiese Bockmann, senior maritime-intelligence analyst at Windward.