Early this month, one Iranian and one Israeli tweet created a storm in the already troubled waters of the Mediterranean Sea.

On June 26, the Iranian Embassy in Lebanon wrote a vaguely worded tweet with a picture of an Iranian ship and said that Iran did not need America’s approval to send fuel to Lebanon. The tweet implied the ship carried fuel and was headed to Lebanon. Fearful of U.S. sanctions, Lebanon’s energy ministry quickly denied ever requesting to import Iranian fuel, but not before speculation was rife that an Iranian tanker was on its way to the port of Beirut.

Then, on July 6, IntelliNews, a blog on Israeli defense and intelligence affairs, tweeted that Iran had dispatched Arman 114, an Iranian-flagged ship carrying Iranian crude, to Lebanon. “Hezbollah is conducting a logistical operation to smuggle Iranian fuel into Lebanon,” the tweet read. A few days earlier, Hezbollah’s chief Hassan Nasrallah had pledged to import fuel from its patron Iran to emerge as the savior of a country reeling under a devastating shortage of the essential commodity.

Together, the tweets seemed to suggest the expansion of a war between Israel and Iran that had until now mostly taken place in the shadows. For years, Iran and Israel have engaged in tit-for-tat attacks on each other’s ships in, and beyond, the Mediterranean. The conflict has mostly concentrated on Iranian oil tankers bound for oil-starved Syria. Now it seems the fight is spreading to involve a Lebanon that increasingly seems on the verge of economic collapse.

Arman 114 finally anchored at the Baniyas port in Syria on June 13. TankerTrackers, an online service that tracks and reports shipments of crude oil, said that it had been tracking Arman 114 along with two other ships carrying Iranian crude and confirmed Baniyas, not Beirut, turned out to be their final destination. “Latest satellite imagery confirms that all three Iranian tankers went to Baniyas, Syria as planned,” TankerTrackers tweeted. But the Iranian Embassy’s tweet seemed to be mere posturing. It appears the embassy used a stock photo of a ship and in reality there was none en route to Lebanon.

Immediate worries of an escalation between Israel and Iran were warded off but Israel’s strategy to target Iranian oil tankers is still very much active. Iran’s determination to respond in kind and attack Israel’s commercial vessels or those of America’s allies in the Gulf, has not weakened either.

Arman 114’s smooth journey illustrated the ease with which Iran has been defying U.S. sanctions. It also displayed that despite U.S. and Israeli awareness of the movement of specific Iranian oil tankers violating sanctions, neither country can stop all such transactions. The United States is constrained by international law and, like Israel, must fear Iranian retaliation. Iran controls the Strait of Hormuz, a 21-mile-wide strategic waterway through which 20 percent of the global oil supply passes.

Farzin Nadimi, an associate fellow with the Washington Institute for Near East Policy and an expert in the security and defense affairs of Iran and the Persian Gulf region, said technically a ship in international waters cannot be stopped unless it violates international maritime law or unless the flag state allows it. “If it is known to carry contraband such as drugs, or weapons of mass destruction, there are U.S. laws that allow stopping and searching in the high seas, or under some circumstances such action can even be justified under universal jurisdiction,” Nadimi said. “The U.S. Congress can also pass a law, or the president may issue an executive order sanctioning individual tankers and ask other countries to stop them as soon as they enter their territorial waters, or face sanctions themselves.”

Nadimi added that Iran has one of the largest tanker fleets and a lot of experience in how to conceal the movement of its oil cargoes. Iran regularly changes the flags on its ships, renames tankers, and turns off their automatic identification systems to avoid being tracked. Moreover, according to a U.S. Treasury report, Iran deployed a range of front companies with help from Hezbollah to be able to sell its oil despite the sanctions.

“Even when we could track movements of Iranian tankers there was a lack of will within the U.S. government to stop them, not only because of constraints of international law but also because the U.S. was just worried about Iran’s retaliation in the Persian Gulf,” Nadimi said. “Iran has proved it can do some nasty things,” he added, alluding to alleged Iranian attacks on Saudi, Emirati, and other vessels. Iran even seized a British-flagged tanker, the Stena Impero, in July 2019, in retaliation for Gibraltar seizing a Syria-bound Iranian oil tanker, the Grace 1, two weeks earlier.

Experts say that while U.S. sanctions have succeeded in blocking the movement of money through banking channels, they achieved little success in stopping Iran from selling crude at reduced prices for cash. Energy analysts have seen a steady rise in Iran’s oil exports since late last year. According to United Against Nuclear Iran, an advocacy group and a critic of the 2015 nuclear deal, Syria received the second-most oil barrels from Iran since December 2020; many times more were exported to China.

Under recently unseated Prime Minister Benjamin Netanyahu, Israel was accused of attacking a dozen Iranian ships, mostly those carrying fuel to Syria and some supplying arms to Iran’s proxies, but none headed toward China. In April this year, Israel attacked an Iranian vessel called MV Saviz that was anchored in the Red Sea and suspected to be a floating armory for Iran-backed Houthis in Yemen. From the Israeli perspective it was an Iranian naval outpost in the Red Sea that endangered safe navigation of Israeli cargo.

Israel’s new Prime Minister Naftali Bennett has held even more hawkish views than his predecessor and has reportedly suggested that Israel must attack Iran whenever its proxies—Hezbollah or Hamas—blow up anything inside Israel. Less than a month after he came to power, Iran accused Israel of targeting a nuclear facility in Karaj reportedly producing centrifuges to replace those damaged in Israel’s previous covert attacks at the Natanz nuclear facility in Iran.

Many Israeli analysts believe that Israel’s covert hits inside Iran and overt airstrikes in Syria on Iran’s arms depots serve Israel’s strategic interests better than naval attacks. The growing consensus among experts seems to be that Bennett must take only calculated risks in the maritime arena while continuing with land, air, and cybersecurity sabotage of Iran’s nuclear apparatus. They are unsure, however, whether Bennett, who is eager to come across as even more unforgiving of Iran than Netanyahu, would listen.

Eran Lerman, a former deputy national security advisor for the office of the Israeli prime minister, said that Bennett’s policy would differ from Netanyahu’s only in his dealings with Biden—with whom he would aim to keep differences behind closed doors instead of making a public spectacle of them—while maintaining a tough stand against Iran. “His intention would be to not undermine the Biden administration but to retain Israel’s right to act freely,” Lerman said.

Others said Israel must avoid getting dragged into a dangerous naval conflict. Shaul Chorev, a retired Israeli rear admiral who heads the Maritime Policy and Strategy Research Center at the University of Haifa and previously led the Israel Atomic Energy Commission, advises caution. “Attacking Iranian tankers neither discourages Iran from enriching uranium nor from bankrolling Hezbollah and other proxies,” Chorev said. “A naval conflict comes at a high cost to us too, especially in areas in the Persian Gulf and the Arabian Sea which are outside the range of the Israeli Navy and its ability to protect Israeli-owned vessels sailing in this region.”

Meanwhile, the people of Lebanon continue to struggle with fuel scarcity. If the naval war between Israel and Iran expands, that struggle will last a while longer yet.