The Iranian-backed Houthis sent a letter to the European Union on September 10 pledging not to target European vessels in the Red Sea, even as the group escalates its offensive along Yemen's southern coast.

The outreach coincides with the sharpest rebound in container shipping through the Bab al-Mandeb in nearly three years. Capacity through the strategic waterway linking the Red Sea to the Gulf of Aden has reached almost 30% of pre-2023 levels, the highest since October 2023, according to maritime analytics firm Xeneta.

What's behind the container rebound?

Carriers Maersk and CMA CGM have restored services through the Suez Canal in recent weeks, pushing vessel numbers through Bab al-Mandeb to their highest in almost three years. The traffic has returned without a corresponding wave of strikes.

"There has been no attack on container ships for over a year, despite the increasing number of ships transiting through Bab al-Mandeb. So I think the absence of intent is verified in the data," Maersk chief executive Vincent Clerc said.

Clerc said routing decisions are taken daily using intelligence from US, UK and NATO sources. The Houthis have separately told Washington they will not target American vessels after Oman-brokered talks with the Trump administration.

"They don't want us to go after them," US President Donald Trump said this month. "They're letting most ships go through. There's just one country that they're not too happy with, and we'll get that straightened out."

Why does September 10 matter?

The Houthi letter to the EU's European External Action Service arrived the same day rebels seized the Yemeni port of Mocha, two diplomats briefed on the matter said. Within weeks, Houthi fighters captured several islands in the Red Sea and Bab al-Mandeb after pushing back Saudi-aligned forces.

The militants are framing their campaign as limited to Saudi Arabia rather than a broader effort to disrupt international shipping. The European External Action Service did not immediately respond to a request for comment.

Why are tanker owners still cautious?

Tanker operators have moved more slowly. Over the past month, fewer tankers have loaded cargoes at Saudi Arabia's Yanbu terminal, marine data firm Windward reported. Tankers typically sail through the Bab al-Mandeb with GPS active, then switch off signals approaching Saudi ports to obscure cargo origins.

The Houthi escalation has unnerved tanker owners at a time when Iran is throttling traffic through the Strait of Hormuz as part of its confrontation with the United States.

What military deployments are forming?

French President Emmanuel Macron said Thursday that France will send soldiers, radar systems and air defences to Yanbu, which hosts critical oil infrastructure, but stressed the deployment was designed "not to get us involved in any conflicts."

Britain said this week it would deploy a Royal Air Force Voyager refuelling aircraft to Saudi Arabia for "defensive air-to-air refuelling." The United States has so far declined Riyadh's requests for direct support against the Houthis, while continuing defensive assistance.

The EU has operated a naval mission in the Red Sea and Gulf of Aden for more than two years. EU foreign policy chief Kaja Kallas said ministers meeting in New York this week "raised the worsening situation in the Red Sea, which is already affecting European interests," adding that "Houthi attacks also sabotage the global economy."

The EU and Saudi Arabia are in talks on combining their maritime task forces. Riyadh announced in July a separate naval coalition with about a dozen regional states.

What's the forward picture?

Continued carrier routing through the Suez and Bab al-Mandeb will hinge on whether the absence of containership strikes — the data Clerc highlighted — holds, and on whether the parallel Saudi-Houthi flare-up draws additional Western military assets to Yanbu before the next Asia-Europe service additions are scheduled.