Yemen: Regional Escalation Reawakens Houthi Maritime Threats

What happened: Yemen’s Houthis announced a “complete ban” on Israeli maritime navigation in the Red Sea as part of their response to ongoing regional escalation.

Why it matters: The first official Houthi announcement of a Red Sea blockade during the Iran war increases the systemic risk for shippers using Bab al-Mandab.

What happens next: We still view the Houthis as hesitant to get involved in the Iran War, and foresee the group pursuing a narrow interpretation of “Israeli maritime navigation” in implementing their ban, leaving most traffic through the Bab al-Mandab unaffected.

On 8 June, Houthi military spokesman Yahya Sarea claimed responsibility for the first Houthi missile attack on Israel since April. Framing the attack as a response to US-Israeli escalation in the Iran War, Sarea went on to announce a “complete and total ban on Israeli maritime navigation in the Red Sea.”

Coming as the Houthis have largely sat out the Iran war, the somewhat vague announcement is nevertheless an escalation that Bab al-Mandab shippers should take seriously. The Houthis do not issue conditions they do not intend to impose, and a spike in Somali pirate activity in the Gulf of Aden with ambiguous links to the Houthis has already made the waterway more treacherous.

However, the announcement’s purposeful vagueness also gives Houthi leadership some wiggle room, and we still see the movement as hesitant to join the Iran war.

Based on this and the Houthis' conduct during their 2023-2025 Red Sea campaign, we consider the threat to non-Israel-flagged and -owned vessels unchanged, with the group likely leaning toward a stricter interpretation of “Israeli maritime navigation” that leaves Yanbu-bound tanker traffic unaffected. However, this could expand to include broader targets depending on regional escalation, and there remains a heightened risk from Somali pirate activity.

Figuring Out the Phase of Escalation

While messier in practice, Houthi Red Sea attacks are, in theory, highly structured affairs. Presenting themselves as imposing a “deterrence equation” on their adversaries in 2023-2025, the group framed their attacks as occurring in “phases of escalation.” Earlier phases targeted smaller subsets of ships, such as Israel-flagged vessels, and later phases focused on larger ships, like those belonging to companies doing business with Israel.

Despite threats to close the Bab al-Mandab, until 8 June, the Houthis had not declared the Red Sea off-limits for any ships during the Iran War. However, that doesn’t mean they haven’t had a hand in maritime threats. While still fuzzy, there is evidence of at least transactional Houthi collaboration with pirate networks in Somalia, which have attacked several ships in recent months, including a 9 June attack on a cargo ship off Balhaf, a day after Sarea’s announcement.

Regardless of their involvement in these attacks, the Houthis’ public announcement of an Israeli ship does represent a substantive escalation in their stance. While they’ve been willing to hint at escalation in recent months, the group has been careful not to commit officially, and Sarea would not have made his announcement if the group was not prepared to back it up.

However, the Houthis have also been uncharacteristically quiet about what is supposedly a major change. Sarea’s announcement has not been hyped in Houthi media; the Houthi agency responsible for managing the group’s blockades has not issued directives; Abd al-Malik al-Houthi (see Featured Personality) has not issued a sermon or announced a new “phase of escalation”; and there has as yet been no actual shipping attack.

A Hesitant Notch Up the Escalation Ladder

This silence, combined with claims from Houthi sources that the group is explicitly saving attacks on ships calling at Israeli ports for later escalations, contributes to our view that the Houthis remain quite hesitant to get drawn into regional conflict and have adopted the minimum acceptable escalation in response to US-Israeli attacks on their allies.

While they now appear ready to attack any Israeli-flagged or -owned ships, the fact that such ships have already largely abandoned the Red Sea means they may not be called to. Unlike during their 2023-2025 campaign, when their desire to carry out attacks saw the Houthis get creative with the definition of what ships were “Israel-linked,” we don’t yet expect the group to target ships for being owned by companies that do business with Israel or even ships calling at Israeli ports.

Most importantly, we expect the Houthis to remain quite circumspect about targeting traffic to and from Yanbu — a move that would invite the wrath of Riyadh, which has adopted a more conciliatory stance toward both the Houthis and their ally, Iran, than other regional powers.

However, risks remain. If at some point Israel or the US retaliates with direct strikes against the Houthis, an escalation spiral in which the Houthis rapidly expand their conditions for attack is likely. Further statements from Sarea outlining restrictions or an address from Abd al-Malik al-Houthi announcing a phase of escalation would be signs of growing danger.

Moreover, as demonstrated by Somali pirates’ 2 May seizure of the tanker MT EUREKA off Yemen’s coast, voyages around Yemen already experience elevated risk, and investors are advised to maintain heightened vigilance even if the Houthis’ actions remain limited.