Oil markets are entering a new phase of uncertainty after the U.S. joined the war between Iran and Israel, with experts warning of triple-digit prices.

Investors are closely watching for Tehran’s reaction following the U.S.′ strikes on its nuclear facilities, with Iran’s foreign minister warning his country reserved “all options” to defend its sovereignty.

Oil futures were up over 2% as of early Asia hours. U.S. WTI crude rose more than 2% to $75.22 per barrel, while global benchmark Brent was up nearly 2% at $78.53 per barrel.

“There is real risk of the market experiencing unprecedented supply disruptions over coming weeks, of a much more severe nature than the oil price shock in 2022 in wake of the Ukraine war,” said MST Marquee’s senior energy analyst Saul Kavonic.

While the market reaction post U.S. strikes has been less aggressive, relative to just over a week ago when Israel launched airstrikes against Iran, industry watchers believe that the latest developments usher in a new era of volatility for the oil markets, especially as they await for potential Iranian countermeasures.

Threats of blocking Strait of Hormuz, after Iran’s parliament approved closing it as per state media, have added to market jitters.

The strait, which connects the Persian Gulf to the Arabian Sea, is a critical artery for global oil trade with about 20 million barrels of oil and oil products passing through it per day. That makes up almost one-fifth of global oil shipments.

If Iran does close the Strait of Hormuz, Western forces will likely “directly enter the fray” and try to reopen it, Kavonic told CNBC, adding that oil prices could approach $100 per barrel and retest the highs seen in 2022, if the closure goes beyond more than a few weeks.

“Even a degree of harassment of passage through the Strait, short of a full closure, could still see a serious heightening of oil prices,” said the senior energy analyst.

Kavonic’s view is echoed by other industry experts.

The U.S. and allied military would eventually reopen the Strait, but if Iran employed all its military means, the conflict could “last longer than the last two Gulf Wars,” said Bob McNally, president of Rapidan Energy Group. And should Iran decide to attack Gulf energy production or flows, it has the capability to disrupt oil and LNG shipping, resulting in sharp spike in prices.

“A prolonged closure or destruction of key Gulf energy infrastructure could propel crude prices to above $100,” he said.

The CBOE crude oil volatility index, which measures the market’s expectation of 30-day volatility in crude oil prices, is at March 2022 levels it hit shortly after Russia invaded Ukraine.

While there has been some level of uncertainty with regards to how developments in the Middle East could play out for oil supplies, Lipow Associates’ Andy Lipow noted that the current developments carry a different weight.

“This time feels different, given the barrage of missiles that have been fired for over a week and now the direct involvement of the USA,” he said, adding oil could hit $100 per barrel should exports through the Strait of Hormuz be affected.

While an attempt to block the Hormuz waterway between Iran and Oman could have profound consequences for the wider economy, threats of blocking the strait have mostly been rhetorical, with experts saying that it is physically impossible to do so.

“So the picture is a little bit mixed, and I think traders will err on the side of caution, not panicking unless there is more real evidence to do,” said Vandana Hari, founder and CEO, Vanda Insights.

Iran in 2018 threatened to close the Strait of Hormuz amid heightened tensions after the U.S. exited the nuclear deal and reinstated sanctions. Similar threat were issued in 2011 and 2012, when senior Iranian officials — among them then–Vice President Mohammad-Reza Rahimi — warned of a possible closure if Western nations imposed more sanctions on Iran’s oil exports over its nuclear activities.

Additionally, it is worth noting that Iranian energy infrastructure has not been a target thus far even with the recent conflagrations, said Rebecca Babin, senior energy trader at CIBC Private Wealth.

“It appears that both sides have an incentive to keep oil out of the line of fire, at least for now,” she said.