Ansar Allah (Houthi movement) — The United States in the Gulf

Summary

From November 2023 the Houthi movement attacked commercial shipping in the Red Sea and Gulf of Aden; the United States led a coalition naval response from December 2023 and conducted strikes in Yemen from January 2024, and a further campaign in March–May 2025 that ended with an Oman-mediated understanding under which the two sides stopped targeting each other. The movement did not renounce action against other parties. Through the 2026 war it engaged selectively against Israel and, from July, opened a campaign against Saudi shipping and territory; the United States Fifth Fleet continues to command the coalition structures whose water the movement now sits beside, and United States officials were reported in September 2026 to have offered Saudi Arabia intelligence support while declining direct strikes on the Houthis. No strike by either party on the other has been recorded since May 2025.

Why it matters

Whether the Bab el-Mandeb advance becomes a coalition problem rather than a Saudi one turns on this relationship. The movement has kept Saudi shipping as its declared exception and left everyone else's alone; the United States has kept its war to Iran and left Yemen alone. Either boundary failing would change what the outlet of the Hormuz bypass depends on.

Agreements

• Oman-mediated United States–Houthi understanding · signed 2025-05

  Announced by Oman as a mutual undertaking not to target each other, including United States vessels in the Red Sea and Bab el-Mandeb. No text published; it did not cover the movement's action against other parties.

Related events

• The Houthi movement blockades shipping to and from Saudi ports Jul 2026

  Maritime · Energy

• A Saudi-led multinational maritime defence alliance is declared in Riyadh 30 Jul 2026

  Maritime · Diplomatic

• The Houthi movement takes the southern Red Sea coast and reaches Bab el-Mandeb 10 – 11 Sep 2026

  Territorial change · Maritime

Organisations

Structures through which this relationship operates. Not parties to it — the parties are the two actors above.

Places

Markers this module already publishes. This record adds no geographic precision of its own.

What remains unknown

• The two parties characterise the 2023–25 campaign incompatibly — the movement as action against shipping linked to Israel and its supporters, the United States (which designated the movement a foreign terrorist organisation in 2025) as attacks on international shipping. Vigil adopts neither characterisation.
• The content of the May 2025 understanding is known only from Oman's announcement and the parties' statements; whether it covers the coalition task forces as such is not established.
• The reported September 2026 United States decision not to strike the Houthis rests on unnamed officials; no government has published it.

Readings the evidence also supports

• The absence of a United States strike since May 2025 is consistent with an observed understanding, with a deliberate boundary around the Iran war, and with a lack of occasion; the record does not choose.

Listed because the record's own assessment is not the only one its sources permit — not as a hedge on the assessment above.