Who are the Houthis? Asymmetric warfare in the Red Sea

Who are the Houthis? Much of the world started asking in late 2023, when an armed movement from northern Yemen began attacking merchant ships in the Red Sea and pushed many shipping lines to sail around Africa instead. Officially called Ansar Allah ('supporters of God'), the group has become a textbook case of asymmetric warfare: an actor with limited means using relatively cheap drones and missiles to impose huge costs on major powers and on the global economy.

This timeline covers verified milestones up to 2025. The situation continues to evolve, so later developments should be checked against up-to-date sources such as the UN Panel of Experts on Yemen or ACLED.

At a glance

• Name: Ansar Allah, known as the Houthis after the al-Houthi family that founded the movement.
• Origins: a Zaydi revivalist movement — Zaydism being a branch of Shia Islam rooted in northern Yemen — that emerged in Saada province in the 1990s.
• Territory: the capital, Sanaa, and much of the north-west, home to most of Yemen's population.
• Slogan: includes chants against the United States and Israel, which helps explain its rhetoric in the Red Sea crisis.

Houthi timeline: from Saada to the Red Sea

1990–2014: from religious revival to armed force

1. 1990s: the Believing Youth, a Zaydi educational and religious movement protesting the marginalisation of the north and Saudi influence, emerges in Saada.
2. 2004: the Yemeni army kills its leader, Hussein Badreddin al-Houthi. Six 'Saada wars' (2004–2010) follow against the government of Ali Abdullah Saleh.
3. 2011–2012: the Arab Spring forces Saleh out. The Houthis exploit the vacuum and cast themselves as opponents of the new transitional government.
4. September 2014: they seize Sanaa — paradoxically, in alliance with their old enemy Saleh.

2015–2022: war with the Saudi-led coalition

1. March 2015: a Saudi-led coalition intervenes to restore President Hadi, turning the conflict into a regional war with thousands of airstrikes.
2. December 2017: the Houthis kill Saleh after their alliance collapses.
3. September 2019: attacks on Saudi oil facilities at Abqaiq and Khurais. The Houthis claimed them; the US and Saudi Arabia blamed Iran; the UN Panel of Experts doubted they were launched from Yemen. Responsibility is still disputed.
4. January 2022: missile and drone strikes on Abu Dhabi.
5. April 2022: a UN-brokered truce. It formally lapsed in October but sharply reduced large-scale fighting.

The human toll of this period is immense. A UNDP report estimated that the war had caused around 377,000 deaths by the end of 2021, more than half from indirect causes such as hunger and disease.

2023–2025: the Red Sea campaign

1. October 2023: after Hamas's 7 October attack and the start of the Gaza war, the Houthis fire missiles and drones towards Israel and announce attacks on ships they link to it.
2. November 2023: they hijack the car carrier Galaxy Leader by helicopter. A wave of attacks follows, eventually hitting ships with no apparent connection to Israel.
3. December 2023: the US announces the multinational Operation Prosperity Guardian to protect shipping.
4. January 2024: US and British strikes on Houthi targets in Yemen begin. Washington re-designates the group as a global terrorist entity.
5. February 2024: the EU launches its defensive naval operation, Aspides.
6. March 2024: the Rubymar becomes the first ship sunk, and three crew members of the True Confidence are killed in the first deadly attack.
7. July 2024: a Houthi drone kills a man in Tel Aviv; Israel strikes the port of Hodeidah.
8. March–May 2025: the US launches a large-scale air campaign. On 6 May Oman announces a ceasefire between Washington and the Houthis that does not cover Israel.
9. July 2025: the Houthis sink the bulk carriers Magic Seas and Eternity C, showing the threat to shipping had not gone away.

Why their asymmetric strategy works

• Cost imbalance: defence analysts have stressed that shooting down low-cost drones with interceptors worth millions of dollars is unsustainable over time.
• Geography: the Bab el-Mandeb strait is about 30 km wide at its narrowest, and traffic between the Indian Ocean and the Mediterranean via Suez must pass through it.
• Economic effect without hitting anything: risk alone pushes up insurance and diverts ships around the Cape of Good Hope. UNCTAD estimated in early 2024 that Suez transits had fallen by around 40%.
• Resilience under bombing: after years of Saudi airstrikes, the movement is experienced at dispersing and hiding arsenals in mountainous terrain.
• Political payoff: the attacks boosted its image in parts of the Arab world and its standing against Yemeni rivals.

They don't need to win at sea — they only need to make sure no one can sail in peace.

Editorial summary of the logic of access denial

What is still debated

Iranian proxies or independent actors?

UN Panel of Experts reports have documented missile and drone components consistent with Iranian manufacture, and the US has seized arms shipments in the Arabian Sea; Iran denies arming the group. Many specialists describe the relationship as an alliance with autonomy: Tehran provides technology and backing, but the Houthis have their own agenda, social base and history, all of which predate that relationship.

Have they won?

It depends on the yardstick. They have not stopped the war in Gaza, their declared aim, and they have endured heavy bombing. But they have shown that a non-state actor can disrupt one of the world's main trade routes for more than a year and force several navies into a costly escort mission.

Conclusion

In three decades the Houthis went from a regional religious movement to rulers of Yemen's capital and a challenge to international shipping. Their story distils the trends of asymmetric warfare today: cheap, accessible technology, exploitation of geographic chokepoints, and a logic in which the goal is not military victory but making the opponent pay a price it does not want to pay.