China was the main beneficiary of the so-called “peace window” during which negotiations were under way between the US and Iran and before a return to violence in the Strait of Hormuz, according to economist Javed Hassan.

“Of the extra five to six million barrels per day during the pause in hostilities, almost two-thirds reportedly flowed directly to China, leaving less than two million barrels per day for the rest of the world,” Hassan told Al Jazeera.

In contrast, Hassan said, the US energy position was less comfortable. “The US’s Strategic Petroleum Reserve remains near multi-decade lows, while inventories at Cushing are already relatively tight,” he said.

“If the Strait of Hormuz were to close again, forcing sustained withdrawals of two to three million barrels per day for several weeks, oil prices could move well above $100 a barrel,” he said.

Hassan said that while the ceasefire bought time, it did not resolve the underlying issue. “Both sides appear to have used the pause to prepare for the next phase of confrontation,” he said. “We may yet be facing a long, and very expensive, summer.”

The US bombed a strategically important railway bridge in northern Iran, linking it to China and Russia, according to Iran’s Fars news agency.

The Ogtay Khan rail bridge in Golestan province was reportedly attacked by a US cruise missile on Thursday morning.

The bridge connects a strategic chokepoint on Iran’s railway corridor with China and Turkmenistan.