The United States and Israel’s strikes on Iran are expected to spark a surge in oil prices when futures trading opens Sunday at 6 p.m. ET, experts warn.

The Organization of the Petroleum Exporting Countries (OPEC) and its allies said early Sunday it would raise its daily output by 206,000 barrels a day after pausing incremental production increases earlier in the year. In the fourth quarter, OPEC boosted production by 137,000 barrels per day.

The production increase may somewhat blunt the expected surge in oil prices when the futures market opens Sunday evening, but energy analysts didn’t expect the production increases to do much to keep prices in check.

Oil prices have been rising in anticipation of an attack on Iran, and on Friday, Brent crude, the global benchmark, rose 2.9% to $72.87 a barrel.

But how much oil gains will depend on how long the military campaign might last and the conflict’s potential impact on the Iran-controlled Strait of Hormuz.

On Saturday, Trump posted on Truth Social that “heavy and pinpoint bombing … will continue, uninterrupted throughout the week or, as long as necessary to achieve our objective of PEACE THROUGHOUT THE MIDDLE EAST AND, INDEED, THE WORLD,” reaffirming earlier comments that the military campaign would be “massive and ongoing.”

Here’s what you need know about the oil market as the military conflict ensues.

Iran plays a pivotal role in the global oil market. It is a major producer of oil, controls a vital shipping lane for crude and exports to oil-hungry nations such as China. The country also boasts the world’s third-largest proven oil reserves, according to OPEC.

The Strait of Hormuz, a narrow waterway off Iran’s southern coast, is the main shipping route for crude from oil-rich countries such as Saudi Arabia and Kuwait to the rest of the world. Iran controls the strait’s northern side. About 20 million barrels of oil, or about one-fifth of daily global production, flow through the strait every day, according to the US Energy Information Administration, which calls the channel a “critical oil chokepoint.”

Iran has threatened to close the vital waterway in previous conflicts with the United States and other Western nations. During Iran’s 12-day conflict with Israel last year, Goldman Sachs estimated that oil prices could blow past $100 a barrel if there was an “extended disruption” to the strait.