The number of vessels navigating the critically important Strait of Hormuz appears to be declining, according to the world’s largest shipping association, amid deepening fears of a widening conflict in the Middle East.

Jakob Larsen, head of security at Bimco, which represents global shipowners, said all shipowners were closely monitoring developments in the region and some have already paused transits in the Strait of Hormuz due to the deterioration of the security situation.

His comments come shortly after the U.S. on Saturday attacked three major Iranian nuclear enrichment facilities, a massive escalation in its involvement with Israel’s effort to cripple Tehran’s nuclear program.

Iran has condemned the attack, saying it reserves all options to defend its sovereignty and people.

“Before the US attack, the impact on shipping patterns was limited,” Bimco’s Larsen said.

“Now, after the US attack, we have indications that the number of ships passing is reducing. If we begin to see Iranian attacks on shipping, it will most likely further reduce the number of ships transiting through the [Strait of Hormuz],” he added.

The Strait of Hormuz, which connects the Persian Gulf to the Arabian Sea, is recognized as one of the world’s most important oil chokepoints.

In 2024 and the first quarter of 2025, for instance, flows through the narrow waterway made up roughly 20% of global oil and petroleum product consumption, according to the U.S. Energy Information Administration. Around 20% of global liquified natural gas (LNG) also transited through the Strait of Hormuz last year, primarily from Qatar.

The inability of oil to traverse through the waterway, even temporarily, can ratchet up global energy prices, raise shipping costs and create significant supply delays.

Yet, in the aftermath of the U.S. attacks on key nuclear sites, Iran’s parliament reportedly approved the closure of the waterway, risking alienating its neighbors and trade partners.

“The pace at which tankers are entering the Strait of Hormuz has definitely slowed. We have indications from shippers that they are putting tankers and vessels on standby, so they are waiting for an opportune moment to enter the Strait,” Critchlow told CNBC’s “Europe Early Edition” on Monday.

“At the same time, there have been reports that suppliers of LNG, for example, in the Gulf have told lifters of LNG to wait before entering, so [as] not to loiter in the Gulf, keep vessels out of that region,” he added.

Japan’s Nippon Yusen, one of the world’s largest ship operators, recently introduced a standby to enter the Strait of Hormuz to limit the length of its stay in the Persian Gulf, according to S&P Global Commodity Insights, citing a company spokesperson.

Nippon Yusen’s policy, which comes as part of a precautionary measure following the escalation of Isreal-Iran tensions since June 13, means ships are asked to pause for a day or a couple of days when there is flexibility in the shipping schedule, S&P Global Commodity Insights reported on Monday.

The company has not implemented a navigation halt in the Strait of Hormuz, however.

Japan’s Mitsui O.S.K Lines also instructed vessels to limit time spent in the Gulf following U.S. strikes on Iranian nuclear facilities, Reuters reported Monday, citing a company spokesperson.

Spokespeople at Nippon Yusen and Mitsui OSK Lines were not immediately available to comment when contacted by CNBC.

German container shipping firm Hapag-Lloyd said it is continuing to sail through the Strait of Hormuz.

“However, the situation is unpredictable and could change within a matter of hours. In this case, our emergency and response plans, which we maintain as part of our crisis management system, come into effect,” a Hapag-Lloyd spokesperson said.

The U.S. joining the war between Israel and Iran might seem like a geopolitical flashpoint that would send markets tumbling. Instead, investors are largely shrugging off the escalation, with many strategists believing the conflict to be contained — and even bullish for some risk assets.

As of 1 p.m. Singapore time, the MSCI World index, which tracks over a thousand large and mid-cap companies from 23 developed markets, declined only 0.12%. Safe havens are also trading mixed, with the Japanese yen weakening 0.64% against the dollar, while spot gold prices slipped 0.23% to $3,360 per ounce. The dollar index, which measures the U.S. dollar against a basket of currencies, rose 0.35%. 

In general, the market reactions after the U.S. strikes have been less aggressive, especially relative to just over a week ago when Israel launched airstrikes against Iran.

“The markets view the attack on Iran as a relief with the nuclear threat now gone for the region,” said Dan Ives, managing director at Wedbush, adding that he sees minimal risks of the Iran-Israel conflict spreading to the rest of the region and consequently more “isolated.”

While the gravity of the latest developments should not be dismissed, they are not seen as a systemic risk to global markets, other industry experts echoed.

On Saturday, U.S. President Donald Trump said that the United States had attacked Iranian nuclear sites. Traders are now keeping a close eye on any potential countermeasures from Iran following the U.S. strikes on its nuclear facilities.

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

Investors are closely watching for Iran’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.