A Houthi fighter mans a machine gun mounted on a truck during a parade for people who attended Houthi military training as part of a mobilization campaign, in Sanaa, Yemen, Dec. 18, 2024. Photo: REUTERS/Khaled Abdullah

Saudi Arabia has weathered Iran’s closure of the Strait of Hormuz by relying on its east-west pipeline to send crude from the kingdom’s energy-rich eastern province to the Red Sea terminal of Yanbu. The port exports averaged more than 4 million barrels per day (bpd) in June and early July — still a far cry from the more than 7 million bpd the kingdom exported in February, but better than other Gulf states with limited or nonexistent Hormuz alternatives.

But this pathway is vulnerable. The Houthis have their sights set on disrupting Saudi Arabia’s alternative to the Persian Gulf to pressure their neighbor to the north. The Iran-backed terror group hopes escalation against Riyadh will earn them concessions that improve their position in Yemen while increasing Iran’s leverage against the United States. The Houthis aren’t planning to achieve this only through a maritime blockade. They are also targeting Saudi energy infrastructure.

Prior to the US-Israel war with Iran that began at the end of February, roughly 20 percent of the world’s oil flowed through the Persian Gulf and its southern chokepoint, the Strait of Hormuz. As that flow declined after Iran’s closure of the maritime passageway, exports via the Red Sea chokepoint of Bab al Mandeb surged from around 4.2 million bpd in 2025 to 7.4 million bpd in June, according to data from the maritime intelligence firm Kpler. Most of this oil came from Saudi Arabia.

When the Houthis announced a complete maritime blockade of Saudi Arabia on July 20, it wasn’t immediately obvious how the group — which lacks the naval capability to deny access to Saudi ports — meant to impose it. Despite assurances from the Saudi Ministry of Foreign Affairs that the country is “taking all necessary measures to protect its ships,” the shipping industry began rerouting vessels to avoid Bab al Mandeb even before the Houthis attacked a vessel. But the group didn’t wait long to clarify that it was willing to back this threat with force.

Just two days after the announcement, the Houthis claimed attacks on two Saudi vessels in the Red Sea, though officials in Riyadh only confirmed one was struck. Still, the Houthis have never needed a 100 percent success rate in their attacks to deter shippers. A threat, a few attacks, and very quickly insurance prices spike for vessels transiting the Red Sea while many ships start avoiding the waterway, some opting for the multi-week voyage around Africa.

The energy markets reflect this instability. After the Houthis’ July 22 attack on at least one Saudi tanker, Brent crude, the international oil benchmark, reached more than $100 for the first time since before the June 17 US-Iran Memorandum of Understanding. The price has since fallen under $90.

However, vessels belonging to certain countries can safely transit the maritime passageway. One very large crude carrier (VLCC), Xin Long Yang, left Yanbu on July 20 bound for China via Bab al Mandeb but turned around after the Houthi announcement. The vessel then reversed course again and sailed through the chokepoint. Lloyd’s List, citing knowledgeable sources, said, “Chinese tankers that have already completed loading at Yanbu and are on their return voyage are able to negotiate passage with the Houthis, though clearance is being handled on a ship-by-ship basis.”

The trend continued in the week following the blockade announcement. Vessels linked to China, Russia, and Pakistan — all countries friendly to Iran — have safely transited the waterway. But these ships aren’t the only ones doing so. Saudi vessels have “gone dark” — i.e., turned off their ship tracking data known as automatic identification systems (AIS) — in order to do so as well. This is a viable, though imperfect, alternative. It does not guarantee that the Houthis can’t target a ship, so many shipping companies and insurers are not sufficiently confident in the safety of a dark voyage to risk transiting Bab al Mandeb.

Thus, while shipping is risky and declining, the Houthis are turning their attention to Saudi oil infrastructure.

To be sure, Riyadh sought to deter the group’s attacks. After the July 22 Houthi attack, Saudi Arabia struck Houthi-controlled Hodeidah on Yemen’s west coast, a key region from which the group launches attacks on the Red Sea. The spokesman for the Saudi-led coalition, Major General Turki al-Maliki, described the strike as a “firm, resolute, and proportionate military response.”

Still, the Houthis escalated, targeting energy infrastructure on the Saudi Red Sea coast on July 25. Yahya Saree, the Houthi military spokesman, claimed drone and missile attacks on Aramco facilities at Yanbu and Jazan. Greek-operated missile defenses intercepted the attack on Yanbu. Jazan wasn’t so lucky. Satellite imagery confirmed a fire at the refinery, which is located on the southern end of Saudi Arabia’s coast near Yemen and processes about 400,000 bpd.

Then, Saudi Arabia attributed a July 27 attack on its energy infrastructure to Iran-backed militias in Iraq; the Houthis, however, claimed responsibility. Iraqi militias are behind hundreds of attacks on Saudi Arabia during the conflict begun in February. While Riyadh did not offer details, satellite imagery showed a fire at Abqaiq, the world’s largest processing and stabilizing facility, which was forced to suspend operations. Abqaiq processes up to 7 million bpd, historically more than half of Saudi exports, and is currently sending most of its output through the east-west pipeline to Yanbu. A previous attack on Abqaiq in 2019, again claimed by the Houthis but attributed by American officials to Iran, took over half of Saudi’s oil production temporarily offline.

The Houthis are calibrating their attacks to maximize pressure on Saudi Arabia, but the resulting strain on international energy markets is no accident. In response, the international community needs a coherent strategy for the Houthis. Air campaigns can damage them, but until there is substantial commitment to preventing their rearmament and supporting the internationally recognized Yemeni government in driving the group out, they will continue to squeeze a critical maritime position.

Bridget Toomey is a research analyst at the Foundation for Defense of Democracies, where she focuses on Iranian proxies.