Oil tops $90 as Middle East fighting escalates

Oil prices jumped above $90 per barrel Sunday in the first major trading since the deaths of three U.S. service members and escalating Middle East hostilities.

Why it matters: Higher oil prices could quickly translate into more expensive gasoline for consumers and diesel for freight carriers while increasing inflation risks worldwide.

Context: Brent crude's move above $90 a barrel — its first since mid-June — builds on last week's gains after the U.S.-Iran ceasefire deteriorated further, reducing tanker traffic through the Strait of Hormuz following a brief rebound.

• The nationwide average U.S. gasoline price was just below the politically important $4-per-gallon mark Sunday, per AAA, and is likely to rise above that level Monday.

Catch up quick: The weekend brought further signs that the U.S.-Iran agreement and ceasefire have given way to renewed and expanding strikes.

• That includes reported Iranian attacks on oil and electricity infrastructure in Kuwait.

Threat level: Iran's Supreme Leader Mojtaba Khamenei on Saturday accused President Trump of violating the U.S.-Iran agreement.

• He pledged a strong response by Iran and its proxies if the fighting continues to escalate.
• Trump told NewsNation that he "couldn't care less" about the Iranian leader's comments about the agreement.

What we're watching: Oil markets have proven surprisingly adaptable to the crisis, due to factors like reduced Chinese imports, governments' coordinated releases from stockpiles including the U.S. Strategic Petroleum Reserve, and ample commercial stockpiles.

• But analysts warn that these shock absorbers that prevented even larger price spikes earlier in the crisis are eroding.
• And the market for refined products is facing particular woes, including the effectiveness of Ukraine's drone attacks on Russian refineries, which prompted Russia to ban diesel exports.