In the past two weeks, the Islamic Republic has thrice attacked its enemies at sea, posing a danger to global commerce. Farzin Nadimi explains:

On August 4, personnel from Iran’s Islamic Revolutionary Guard Corps (IRGC) boarded the Emirati bitumen tanker Asphalt Princess in international waters near Fujairah and tried to divert it into Iranian waters. The crew managed to foil their plan by disabling the ship, and the boarding party left when a U.S. Navy destroyer approached.

The incident came just five days after a suspected Iranian suicide drone crashed into the Israeli-operated oil tanker Mercer Street near the Omani port of Duqm. Following an unsuccessful attack on July 29, a drone ripped through the ship’s accommodation area on July 30, killing the Romanian captain and a British security guard. Although maritime confrontations involving Iran, Israel, and the Gulf states have been occurring for years, the nature of the latest incidents highlights the urgent need for collective international action.

In the 1980s, Nadimi notes, Tehran similarly threatened international commerce, attacking tankers belonging to nations that had provided support for Baghdad in the ongoing Iran-Iraq War. Countries that have an interest in protecting the freedom of navigation on the high seas have a lesson to learn from those days:

[Then], the initial U.S., French, and British response—expanding their naval presence in the Gulf region—failed to deter Tehran from targeting ships of all flags. Only after the United States increased its show of military resolve and took bold initiative in using special-warfare tactics did Iran back down.

Indeed, international naval forces already exist that can be used to get the ayatollahs to stand down.

Surveying news websites and social media on Sunday morning, I immediately found some intelligent and well-informed observers arguing that Iran deliberately warned the U.S. of its pending assault on Israel, and calibrated it so that there would be few casualties and minimal destructiveness, thus hoping to avoid major retaliation. In other words, this massive barrage was a face-saving gesture by the ayatollahs. Others disagreed. Brian Carter and Frederick W. Kagan put the issue to rest:

The Iranian April 13 missile-drone attack on Israel was very likely intended to cause significant damage below the threshold that would trigger a massive Israeli response. The attack was designed to succeed, not to fail. The strike package was modeled on those the Russians have used repeatedly against Ukraine to great effect. The attack caused more limited damage than intended likely because the Iranians underestimated the tremendous advantages Israel has in defending against such strikes compared with Ukraine.

But that isn’t to say that Tehran achieved nothing:

The lessons that Iran will draw from this attack will allow it to build more successful strike packages in the future. The attack probably helped Iran identify the relative strengths and weaknesses of the Israeli air-defense system. Iran will likely also share the lessons it learned in this attack with Russia.

Iran’s ability to penetrate Israeli air defenses with even a small number of large ballistic missiles presents serious security concerns for Israel. The only Iranian missiles that got through hit an Israeli military base, limiting the damage, but a future strike in which several ballistic missiles penetrate Israeli air defenses and hit Tel Aviv or Haifa could cause significant civilian casualties and damage to civilian infrastructure, including ports and energy. . . . Israel and its partners should not emerge from this successful defense with any sense of complacency.