Brent crude futures are edging up again this Friday morning, on course to extend a five-day run of rising prices.

The international oil-price benchmark was trading at around $94 a barrel, a level last seen in late July when President Trump warned about the "major military punishment" Iran would face for future Houthi attacks in the Red Sea. Nearly a month later, the Strait of Hormuz is still closed, with an average of 10 and 20 vessels transiting each day compared with 130 or so before the war.

Iran's attacks on commercial shipping this month haven't yet generated an American military response. The Trump administration has now shifted its focus to exerting maximum economic pressure rather than returning to hot war. The strategy shift increases the risk of a prolonged conflict, with continued disruption of oil flow through Hormuz, analysts said.

"Is there a difference between armed conflict and economic warfare? The market does not think so," said Tamas Varga, analyst at London-based oil broker PVM, citing how crude oil rallied nearly $2 a barrel on the news. "After all, it will not rob Iran of the possibility of retaliating, keeping Hormuz shut, and targeting regional energy infrastructure and shipping."