Houthis' Red Sea Attacks
This report has been compiled from Clash Report authors using information from public and private sources to be published in November 2024. Clash Report is a platform that tracks and reports on the world’s conflict zones, the defence industry, security policy and diplomacy, and t
Executive Summary
Impact of Houthis' Attacks on the Red Sea
The Houthi rebel group has significantly escalated their maritime activities in the Red Sea, posing substantial threats to regional stability, global trade, and maritime security. From October 2023 to October 2024, their actions have disrupted commercial and military operations through numerous attacks, driven by specific geopolitical motivations and supported by strategic alliances.
Key Drivers:
• Scale and Frequency of Attacks
• Military and Strategic Capabilities
• Economic Impact
• Strategic Implications
The Houthis frame their operations as support for the Palestinian cause, reacting to Israeli military actions in Gaza. Acting as a regional proxy, the Houthis leverage Iranian support to challenge Israel and its allies by targeting critical maritime chokepoints.
The Houthis launched 132 missile and drone attacks within a year, heavily affecting maritime traffic. Attacks are concentrated along Yemen’s southern coast, from Hawf to the Gulf of Aden and strategic points like Mayyun Island.
The Houthis utilize a mix of missiles, unmanned surface vehicles (USVs), and drones, including new systems like the Toofan-1 USV and Al-Qaria underwater drone. With ballistic and cruise missiles from Iran since 2015, the Houthis have sustained attacks across the region.
Rerouted vessels around the Cape of Good Hope have faced increased transit times (10-14 days) and up to $1 million in additional costs per voyage. Insurance rates for ships in the Red Sea rose by 190%, adding substantial shipping costs. Severe impacts were felt by Egypt, Saudi Arabia, and the UAE, including a 50% reduction in Suez Canal revenues and up to 90% traffic declines in Saudi ports. The disruptions have added an estimated 0.7 percentage points to global core goods inflation.
Trade valued at around $1 trillion has been affected, including disruptions to crude oil and consumer goods shipments. Companies are seeking alternative land routes through Saudi Arabia and the UAE to mitigate the threat to Red Sea trade.
This summary outlines the scope and implications of the Houthis’ Red Sea operations, emphasizing the need for coordinated global efforts to address and mitigate the complex challenges posed by these maritime threats.
Introduction
The Houthi rebel group’s recent escalation of attacks in the Red Sea represents a critical challenge to global maritime security and regional stability. Positioned strategically at the crossroads of international trade, the Red Sea and its key chokepoints, such as the Bab al-Mandab Strait, serve as vital arteries for global commerce, connecting markets in Europe, Asia, and Africa. Since October 2023, the Houthis have launched numerous drone, missile, and unmanned surface vehicle (USV) attacks, primarily targeting commercial and military vessels. These operations, which are often framed as part of a broader geopolitical struggle linked to the Palestinian cause and supported by Iranian influence, have had profound consequences on regional economies, global supply chains, and international security frameworks. This situation report explores the motivations, tactics, and impacts of the Houthi-led disruptions, shedding light on the far-reaching implications of this conflict for the global economy and geopolitical landscape.
Grounds For Houthis Attacks
The Houthis launched their attacks in the Red Sea primarily in response to Israel’s military actions in Gaza. The group announced that their operations were in solidarity with the Palestinian cause, specifically to demonstrate support for Hamas amidst the ongoing conflict with Israel. Their actions targeted shipping routes and vessels in the Red Sea, particularly those perceived to be associated with or benefitting Israel or its allies.
The Houthis have consistently expressed public support for Hamas and the broader Palestinian cause, framing their actions and rhetoric in solidarity with Palestinian groups. Iran’s influence plays a central role in fostering this relationship, as Iran supports a range of groups across the region, including the Houthis, Hamas, and Hezbollah, as part of its “axis of resistance.” Through this connection, there are overlapping interests, with Iran often framing support for the Palestinian cause as central to the broader agenda against Israel and its allies.
The Houthis’ solidarity with Palestine serves their broader political narrative within Yemen and in the regional context, portraying themselves as defenders of oppressed Muslims, which can strengthen their legitimacy among sympathizers.
The Houthis aim to put pressure on Israel and demonstrate their opposition to military action in Gaza. Additionally, the attacks aimed to disrupt the global supply chain and international maritime traffic, given the strategic importance of the Red Sea and the Bab al-Mandab Strait as key global trade routes. This escalation was also sought to draw attention to the wider Israeli-Palestinian conflict and to increase the costs and risks for countries that support or are allied with Israel.
By positioning themselves as the defenders of the Palestinians, the Houthis undoubtedly aim to strengthen their internal legitimacy and increase their appeal among Arab populations dissatisfied with their government’s response to Israel’s actions.
The Houthis have launched more than 130 attacks on commercial shipping since the start of the Gaza conflict, severely disrupting maritime trade routes through one of the world’s critical chokepoints - the Bab-el-Mandeb Strait . Major shipping companies have rerouted their vessels around Africa to avoid the Red Sea, leading to increased shipping costs and longer transit times.
However, the Houthis’ Red Sea strategy is not only related to Gaza. As a proxy, the Houthis have long represented Iran’s political-military presence in Bab-al-Mandab, the Gulf of Aden and the Horn of Africa. It is also intertwined with Iranian-Israeli tensions and other interrelated dynamics in a wider Middle East geostrategic landscape. Iran continues its strategy of pressuring Israel and its allies by threatening critical sea lanes through its long-standing support for the Houthis.
In sum, reason for the Houthis’ strategy of blocking the Red Sea is Iran’s tension with Israel, which regularly uses the military proxy it has acquired through the Houthis in the Yemeni civil war against countries in the region. In this sense, Houthi attacks on Red Sea shipping traffic are a result of Iran’s multifaceted strategy, serving multiple political and military goals.
The Houthi attacks on shipping need to be addressed seriously, even though they do not appear to have had any practical benefit for Iran in terms of their consequences. The Houthi attacks and Iran’s tensions with Israel have necessitated a reassessment of regional military assessments. The capability of Iran and its proxies to influence global trade and stability has recently become more visible in terms of global supply chains and routes, commercial enterprises and their interlocutors, and their impact on the masses.
Houthis attacks on shipping in the Red Sea began on the 19th of October 2023(1). The Houthis fired missiles and drones at Israel and then targeted commercial vessels in the Red Sea. Their declaration that any vessel with links to Israel or its allies would be considered a legitimate target has led to a significant increase in maritime threats in this vital shipping lane.
Since then, the Houthis have carried out numerous attacks, claiming responsibility for over 132 incidents involving missile and drone attacks on various vessels through October 2024, according to ACLED data (2). The campaign has had a significant impact on global trade, with many shipping companies rerouting their vessels to avoid the area.
Houthi attacks on merchant ships are clustered along the southern line of Yemen, from south of Hawf city (14.815903, 54.866814) to the eastern opening of the Gulf of Aden (12.679446, 48.761094) and southwest of Aden Port and northeast of Djibouti Port (12.050044, 44.467310). (See - Chart-1 and Chart - 2)
The centre of concentration of attacks is the line from 6 NM off Mayyun Island (12.566571, 43.353514) to Al-Hudaydah and al Luhayyah, and approximately 40 NM southwest of Farasan Island (16.159405, 41.427125) where the Bab al Mandab passage narrows along the west coast of Yemen. (See Chart 1 and Chart - 2)
The table above shows the dispersion by months after 19 October 2023, when the Houthi attacks on merchant vessel traffic in the Red Sea began, in relation to Israel’s assassinations of Hezbollah and Hamas leaders.
According to the table, the 7-month period in which 81% of the Houthi attacks took place and the subsequent data show that there is no relationship between Houthi attacks and Israeli assassinations. Between Dec 2023 and June 2024, Houthis carried out 108 attacks on merchant vessels in the Red Sea. This seven-month period accounts for 81% of all Houthi attacks.
Houthi Attacks and The Group’s Growing Weapons Inventory
Between 19/10/23 and 22/10/24, 132 attacks were recorded in the Red Sea. In these attacks, the Houthis used tactical weapons. Using combinations of unmanned aerial and naval vehicles and guided missiles, Houthi drones and missiles are frequently used against commercial and military targets, causing both direct damage and significant disruption.
Houthi unmanned surfeace vehicles (USV) are autonomous, explosive-laden and target high-value vessels, demonstrating the group’s increasing sophistication.
In early June 2024, the Houthis unveiled the new Toofan-1 Unmanned Surface Vehicle (3), designed for naval warfare and used in Red Sea attacks. This new addition to their naval capabilities was expected to target both military and commercial vessels in the Red Sea and Gulf of Aden. Characterised by a V-shaped hull that increases speed and manoeuvrability, Toofan-1 can be operated both remotely and manually, and can reach speeds of 150 knots with a warhead weighing 35 kilograms (4).
The Toofan-1 system, which targeted an abandoned ship in the promotional film, started to be used in the Red Sea after the promotion. Last month, in October, the Toofan-1 system was filmed attacking the British oil tanker (5) On 29 October 2024, Yemen’s Houthi forces, also known as Ansarullah, unveiled a new and highly lethal underwater drone, dubbed ‘Al- Qaria (6). The Al-Qaria is an underwater drone, or uncrewed underwater vehicle (UUV), developed and deployed by Yemen’s Houthi movement. Its name, translating to “The Great Calamity” or “The Great Disaster,” references a Koranic verse on Judgment Day. The Al- Qaria features a torpedo-shaped design, enabling it to navigate underwater with stealth.
It is equipped with a camera mounted on an extendable rod toward the rear, allowing operators to survey surroundings by briefly surfacing the camera before submerging again.
Analysts suggest that the Al-Qaria may be derived from the U.S. Navy’s Remus 600 underwater reconnaissance drone, which the Houthis reportedly captured in 2018. The design similarities indicate possible reverse engineering or modification based on the Remus 600 (7).
Footage released by the Houthis shows the Al-Qaria conducting drills, where it skims the water’s surface before executing a precision strike on a stationary target ship(8). This demonstrates its potential effectiveness in maritime operations.
The support the Houthis received from Iran and its eastern allies during the Yemeni çivil war led to the development of their weapons technology (9). This missile capability is capable of actively threatening the Red Sea trade route on an ongoing basis. The Houthi missile capabilities have been bolstered since 2014, with a notable increase in missile strikes against Saudi targets.
They have demonstrated the ability to launch attacks on urban centers and military installations within Saudi Arabia, including Riyadh. The Houthis have also attempted strikes against naval vessels, showcasing their anti-ship capabilities.
Drone Hunting
Yemen’s Houthi rebels have claimed to have shot down multiple U.S. MQ-9 Reaper drones. So far, 12 US MQ-9 Reaper have been shot down in Yemen, according to open sources. Specific incidents include:
According to an April Defence Intelligence Agency report, ‘Since 2015, Iran’s Islamic Revolutionary Guard Corps-Qods Force (IRGC-QF) has been smuggling weapons and weapon components to the Houthis, which has enabled the advancement of the Houthis’ military capabilities. As of 30 April 2024, the Houthis have used Iran-supplied ballistic and cruise missiles to conduct at least 100 attacks against land-based targets in Israel, Saudi Arabia, the United Arab Emirates, and Yemen and at least 56 attacks targeting ships in the Red Sea and Gulf of Aden. Between 2015 and 2024, the United States and its partners have interdicted at least 20 Iranian smuggling vessels, seizing ballistic, cruise, SAM missile components, ATGMs, UAVs, and thousands of assault rifles, rocket components, and other illicit weapons destined for the Houthis. This graphic is focused on Iran’s provision of missiles and missile components to the Houthis because they represent the most technically sophisticated weapons Iran is providing the Houthis.’(10)
In 2016, Houthi ammunition used in a ship attack revealed that the group also transferred weapons and weapons technology from China through Iran. Iran procured around 60 C801- 802 missiles from China to modernise its navy after the Gulf War (11), and later developed its own variant called the Noor missile (12), which the Houthis use under the name Al-Mandeb.
The C-802 is an export version of the YJ-82 anti-ship cruise missile (ASCM) developed by the Chinese Academy of Electro-Mechanical Technology (13).
It is powered by a solid-fuel accelerator that separates after launch before the turbojet engine is engaged, providing a range of 120 km. The missile has a launch weight of 715 kg, of which 165 kg is a semi-armour-piercing high-explosive warhead. The missile has an X-Band (8-12 GHz) radar seeker, which travels 20-30 m above sea level in flight and descends to 5-7 m on final approach (14) With these features, it appears as a suitable tool for the Houthis’ Red Sea attacks. Since 2017, it was known that the Houthis had a drone programme, and in April 2018 the Houthis claimed responsibility for the first attack.
In 2019, they introduced three new suicide drones: Sammad-2, Sammad-3 and Qasif- 2K. Qasif-2K was presented as an improved version of Qasif-1, while Sammad drones were more advanced drones designed to penetrate deep into Saudi territory (15). This drone capacity was also used for Red Sea attacks.
Economic Impact of The Houthi Attacks in The Red Sea
Houthi attacks in the Red Sea have significantly affected regional and global economic transport routes, costs and the economies of large populations and end consumers. The Houthi attacks led to significant increases in transport costs. As a result of the re-routing of ships around the Cape of Good Hope, shipping prices have risen, with prices reportedly reaching 190% over pre-crisis norms (16). This increase is attributed to higher fuel costs, increased insurance premiums and longer transit times, which can add 10 to 14 days to shipping schedules (17).
Regionally, Egypt, Djibouti, the UAE and Saudi Arabia were most affected by the Red Sea incursions. Egypt’s Suez Canal revenues fell by 50%, from $9.4 billion to $7.2 billion in 2024 (18). Djibouti experienced a 33% drop in imports due to disrupted shipping (19). Saudi Red Sea port traffic declined significantly, with a 90% drop at King Abdullah Port and a 70% drop at Jeddah Port (20). UAE port operator DP World recorded a 59% drop in profits (21). Red Sea trade, which accounts for 80 per cent of India’s trade to Europe, was re-routed, resulting in a $30 billion impact (22). Higher insurance costs and disrupted supply chains affected shipping and commodity flows globally. Qatar halted LNG exports through the Red Sea, rerouting shipments and increasing transit times by around nine days. As of mid-September, the average daily transits through the Suez Canal was 29, down from approximately 80 last October (23). During the same period, the average daily trade volüme fell from approximately 4.89 million metric tons to 1.36 million metric tons (24).
On Europe-Asia voyages, diversion to the Cape of Good Hope increases transit time by 30 to 50%, which in turn increases transport costs due to delivery delays and higher fuel consumption. An additional $1 million per voyage can be spent on rerouting. The resulting knock-on effects drive up the price of traded goods on a global scale. In the first half of 2024, JP Morgan Global Research estimates that disruptions in the Red Sea will add 0.7 percentage points to global core goods inflation.
According to the US Defense Intelligence Agency, as of April 2024, the interests of at least 65 countries and 29 major energy and trade companies were directly affected by Houthi attacks (25). The World Bank’s April data draws a striking picture: Starting from January 2024 and peaking in March 2024, the monthly distance
travelled for cargo and tanker vessels has increased by up to 53 percent respectively compared to the pre-conflict period of January- September 2023. This leads to travel time increases of up to 51 per cent for cargo and 39 per cent for tankers, indicating a significant readjustment in global maritime logistics (26).
According to Osama Rabie, chairperson of the Suez Canal Authority (SCA), during a panel at the Global Logistics Forum, since November 2023, over 6,600 vessels have diverted their routes to the Cape of Good Hope (27).
The increase in freight and insurance costs of maritime trade, forced by the attacks in the Red Sea to reroute, encouraged companies to seek safe and short land routes for goods from China and India to reach Europe via Saudi Arabia and the UAE, which are important in port trade.
This new effort to seek a new land route has been necessitated by the additional war risk premiums paid by ships transiting the Red Sea, which have risen from as high as 0.75 per cent to as high as 1 per cent last February (28).
An analysis of trade through the Red Sea from October 2023 to May 2024 reveals that trade totalling an estimated $1 trillion has been disrupted, according to a Russel Group report (29). Crude oil, plastic materials, telephone equipment, cars and clothing were all affected by the attacks.
Conclusion
The ongoing Houthi attacks in the Red Sea underscore a complex interplay of regional politics, military strategy, and economic consequences that resonate far beyond Yemen’s borders. As the Houthis position themselves as defenders of the Palestinian cause, their military actions serve not only to disrupt maritime trade but also to reinforce their legitimacy within a broader narrative of resistance against perceived oppression. The strategic targeting of vessels linked to Israel and its allies illustrates a calculated approach to leverage Iran’s influence in the region, highlighting the Houthis’ role as a proxy in the ongoing Iranian-Israeli tensions.
The significant escalation of Houthi attacks— over 130 incidents since October 2023 has profoundly impacted global shipping routes, forcing major companies to reroute vessels and incurring substantial increases in transport costs. This disruption has reverberated through international supply chains, contributing to inflationary pressures that affect economies worldwide. The economic ramifications are stark: from a 50% drop in Suez Canal revenues to an estimated $1 trillion in disrupted trade, the consequences of these attacks are felt across multiple sectors.
As stakeholders navigate this evolving crisis, it is imperative to recognize the multifaceted nature of the threats posed by the Houthis. These attacks not only challenge maritime security but also necessitate a reevaluation of regional military strategies and international trade policies. The situation demands urgent attention and coordinated responses to mitigate risks and restore stability in one of the world’s most critical maritime corridors. The evolving dynamics serve as a stark reminder of the fragile interconnectedness of regional stability, global trade, and international security in one of the world’s most strategic maritime corridors.
End Notes and Sources:
1. What is the Red Sea crisis, and what does it mean for global trade?”, Guardian, 3 Jan 2024,
2. Yemen Conflict Observatory , Red Sea Attacks: Interactive Map, ACLED Data,
3. Small Agile Houthi Drone Boat Shown Obliterating Ship During Test TWZ
4. İbid.
5. Houthi drone slams into ship, missile hits another in Red Sea attacks, Jerusalem Post,
6. Russia Today, X,
7. Al Qaria vs Remus 600: How Houthi’s New Drone Mirrors US Underwater Tech, Army Recognition,
8. İbid
9. UN Security Council, Panel of Experts on Yemen, 11 October 2024,
10. Seized At Sea: Iranian Weapons Smuggled to the Houthis, US Defense Intelligence Agency, 30 April, 2024,
11. Houthi maritime strike capabilities, European Defence Review, 4 Jan 2024,
12. China and Iran: Resurging Defense Cooperation?, The Institute for National Security Studies, May 10, 2021,
13. Houthi maritime strike capabilities, European Defence Review, 4 Jan 2024,
14. İbid
15. Six Houthi drone warfare strategies: How innovation is shifting the regional balance of power, ACLED, 6 August 2024, Luca Nevola,
16. US Will Spend $1.2 Billion to Restock Arms After Iran, Houthi Attacks, Bloomberg, 3 Oct 2024,
17. Recent threats in the Red Sea: Economic impact on the region and on the EU, Briefing, 27 March, 2024,
18. Revenues of Egypt’s Suez Canal down 60 pct since beginning of 2024, Xinhuanet, 7 Oct 2024,
19. Djibouti trade and investment factsheet 2024, UK government report, 1 Nov, 2024
20. Saudi’s Red Sea box port traffic decimated by Houthi attacks, Lloyd’s List Intelligence, 07 Mar 2024,
21. DP World’s first-half profit more than halves amid Middle East tensions, Reuters, August 15, 2024,
22. India’s exports may take a $30 billion hit on Red Sea threats, Economic Times, 6 Jan 2024,
23. The State of Maritime Supply-Chain Threats, Center for Strategic and International Studies, November 4, 2024,
24. İbid
25. Yemen: Houthi Attacks Placing Pressure on International Trade, US Defense Intelligence Agency, 5 April 2024,
26. The World Bank, Dire Strait: The Far-Reaching Impact of the Red Sea Shipping Crisis, MENA FCV ECONOMIC SERIES BRIEF, Issue 1, April 2024,
27. SCA chairperson: Suez Canal revenues fell to $7.2B in FY23/24 as Red Sea attacks continue, Egypt Today, October 14, 2024,
28. Red Sea insurance nearly doubles after attacked oil tanker appears to leak oil, Reuters, August 28, 2024,
29. Houthi attacks cause $1 trillion of commodities to be disrupted, Safety For Sea, September 13, 2024,