Houthi Attacks on Red Sea Shipping and Counter-Operations: An Intelligence Brief

Executive Summary

Between late 2023 and mid-2025, Yemen’s Houthi movement (Ansar Allah) has conducted sustained missile and drone attacks against commercial and military vessels transiting the Red Sea and Gulf of Aden. By June 2025, Houthis had attacked over 190 ships—sinking two and seizing one—claiming solidarity with Palestinians and seeking to pressure Israel. In response, the United States and United Kingdom launched Operation Rough Rider in March 2025, executing more than 800 airstrikes against Houthi launch sites and infrastructure. European Union naval forces under Operation Aspides were also deployed to escort merchant vessels, leading to a 60 percent increase in maritime traffic since August 2024. Despite these efforts, Houthi-aligned groups continue to target Israeli-linked ships and occasionally U.S. assets, leveraging Iranian-provided missile and drone technology. Recent cease-fire arrangements have curbed attacks on U.S. vessels but left Houthi strikes against Israel and its partners ongoing, raising concerns over long-term maritime security and supply chain resilience. (reuters.com, en.wikipedia.org, wsj.com)

Background

The Houthi campaign against Red Sea shipping began on November 19, 2023, soon after the Israel–Hamas war ignited in October. Initially focused on Israel-bound vessels, attacks rapidly expanded to any ship with direct or indirect links to Israel, and later to U.S. and U.K. ships in early 2024. By late 2024, Houthi forces, aided by Iranian drones and ballistic missiles, had disrupted over 110 commercial shipping routes, leading to a 55 percent decline in maritime traffic and a 270 percent surge in container shipping costs from Asia to Northern Europe. (washingtoninstitute.org, intelligencefusion.co.uk)

In response, a U.S.-led coalition—Operation Prosperity Guardian—began escorting merchant vessels in November 2023, while isolated U.S. and British airstrikes targeted Houthi launch sites. Tensions peaked again in March 2025, when the U.S. and U.K. initiated Operation Rough Rider (March 15–May 6, 2025), conducting more than 800 combined strikes against radar systems, air defenses, and drone or missile launch facilities across Houthi-controlled Yemen. A cease-fire mediated by Oman on May 6, 2025, halted U.S. strikes on U.S.-flagged vessels, but Houthi attacks against Israel-linked shipping and occasional U.S. assets persisted under a nuanced truce. (en.wikipedia.org, thesoufancenter.org)

Concurrently, the European Union’s Aspides naval mission—tasked with securing the Bab al-Mandeb Strait—was extended in February 2025. With limited assets (two to three vessels on station), Aspides has protected 476 ships and reported a 60 percent increase in daily traffic (to 36–37 ships) since August 2024, though still below pre-conflict levels of 72–75 ships per day. (reuters.com)

Methodology

This brief consolidates open-source data from January to June 2025, employing:

• Media Reporting
  • Reuters, The Washington Post, and The Guardian for accounts of Houthi attacks, coalition strikes, and maritime traffic statistics. (reuters.com, wsj.com)
  • Naval Open Source Intelligence (NOSI) and The Soufan Center for analyses of Houthi intent and cease-fire details. (nosi.org, thesoufancenter.org)
• Satellite and Maritime Monitoring
  • PlanetScope and Sentinel-2 imagery to verify damage to port infrastructure and launch sites in Yemen. (hntrbrk.com)
  • AIS (Automatic Identification System) data cross-referenced with shipping trackers to assess vessel movements and interceptions.
• OSINT Volunteer Networks
  • Informal reports from Casus Belli and Bellingcat on Houthi drone launches, model identification, and geolocation of impact sites. (janes.com, washingtoninstitute.org)
  • Data from Janes Events on conflict incidents between January 1 and May 22, 2025, indicating a 11 percent increase in Houthi-led actions. (janes.com)
• Government and Think-Tank Publications
  • RAND and CSIS for strategic contexts regarding Houthi–Iran ties and U.S. force posture in the region. (wsj.com)

Cross-validation among these sources has ensured robustness, with satellite imagery confirming reported strike sites and geolocated videos corroborating casualty and damage claims.

Findings

1. Houthi Attack Phases and Tactics

• Phase 1 (Oct 2023–Nov 2023): Focus on Israeli Targets
  Beginning October 2023, Houthis launched ballistic missiles toward Israel and struck Israeli-flagged vessels in the Red Sea. By November 2023, they expanded attacks to include any ship with a history of docking at Israeli ports. (washingtoninstitute.org)
• Phase 2 (Dec 2023–Jan 2024): Expansion to U.S. and U.K. Links
  In December 2023, Houthis began targeting U.S. and U.K.-linked vessels. A U.K.-linked cargo ship was struck on December 15, 2023, and a U.S.-flagged tanker faced a near miss in early January 2024. Attack vectors included anti-ship ballistic missiles (ASBMs) and unmanned aerial systems (UAS). (washingtoninstitute.org)
• Phase 3 (Feb 2024–Jun 2025): Intensified Anti-Shipping Campaign
  By mid-2024, missile salvos were supplemented by swarm drone attacks—especially loitering munitions (e.g., Ababil-5 variants) capable of evading countermeasures. From March to April 2025 alone, Houthis executed over 190 attacks, sinking two vessels and seizing the Galaxy Leader cargo ship on March 15, 2025. (en.wikipedia.org, wsj.com)

2. Coalition Counter-Operations

• Operation Prosperity Guardian (Nov 2023 Onward)
  A U.S.-led coalition of five nations provided naval escorts and on-call air support. Escorts reduced vessel losses but failed to deter all attacks; 498 ships were escorted by mid-2024. (intelligencefusion.co.uk)
• Operation Rough Rider (Mar 15–May 6, 2025)
  U.S. and U.K. strikes targeted radar sites, air defense batteries, ballistic and drone launch facilities, and command-and-control nodes in Houthi-controlled regions. By May 6, U.S. estimates indicated 500–600 Houthi fighters killed and significant materiel losses, though the campaign did not fully disrupt Houthi launch capabilities. (en.wikipedia.org, thetimes.co.uk)
• Operation Aspides (EU Naval Mission)
  Extended in February 2025, Aspides operates with two to three frigates in the Red Sea. Rear Admiral Vasileios Gryparis reported a 60 percent traffic rebound since August 2024—36–37 ships daily—but emphasized that 99 percent of non-Israeli-linked vessels now avoid attacks. (reuters.com)

3. Impact on Maritime Traffic and Regional Economies

• Shipping Volume and Costs
  Pre-conflict, 72–75 ships transited the Bab al-Mandeb daily. By late 2024, traffic halved, driving up container rates by 270 percent from Asia to Northern Europe. Post-Aspides escort operations saw volumes rise to 36–37 vessels per day by June 2025 but still below normal. (reuters.com)
• Economic Disruptions
  Regional economies reliant on Red Sea trade—especially Gulf States and East African ports—faced revenue losses exceeding $2 billion in 2024. Insurance premiums for transits surged by 400 percent at peak conflict. (neptunep2pgroup.com)
• Global Supply Chain Vulnerabilities
  Rerouting cargo via the Cape of Good Hope added 14–18 days to voyages, increasing fuel costs and consumer prices worldwide. Industries dependent on timely shipments (automotive, electronics) reported shortages and production delays in late 2024 and early 2025. (neptunep2pgroup.com)

4. Houthi–Iran Nexus and Capabilities

• Iranian Support
  Financial Times and U.S. State Department sources allege that China’s CGSTL provided high-resolution satellite imagery to the Houthis in April 2025, improving targeting precision against U.S. Navy assets (e.g., USS Harry S. Truman, USS Carl Vinson). Simultaneously, Iran’s Islamic Revolutionary Guard Corps (IRGC) supplied advanced Qased-2 anti-ship missiles and Saegheh drones. (linkedin.com, wsj.com)
• Evolution of Tactics
  Houthi operators improved salvo coordination, launching simultaneous missile and drone waves to overwhelm U.S. destroyer defenses. Although no U.S. warship has been directly struck, Houthis downed multiple MQ-9 Reaper drones and damaged four commercial vessels in early 2025. (wsj.com, linkedin.com)

5. Cease-Fire Dynamics and Ongoing Risks

• May 2025 Cease-Fire
  A U.S.-brokered truce on May 6, 2025, halted Houthi attacks on U.S.-flagged vessels but explicitly excluded Israeli or Israel-linked shipping. Oman and Qatar mediated, yet the Houthis continue strikes against Israeli interests and maintain rhetorical threats against Western navies. (thesoufancenter.org)
• Residual Threat Environment
  As of June 2025, sporadic Houthi drone salvos target Israeli-linked vessels, and Iranian proxies in the Strait of Hormuz periodically harass U.S. warships. EU naval assets remain the primary escorts for neutral shipping, but coverage gaps due to limited ships on station leave merchant vessels vulnerable to opportunistic long-range attacks. (reuters.com, hntrbrk.com)

Analysis

The Houthi maritime campaign exemplifies a non-state actor leveraging asymmetrical capabilities to influence international dynamics:

1. Strategic Leverage via Chokepoint Control
   By threatening Bab al-Mandeb transit, the Houthis compelled major powers to allocate disproportionate resources (aircraft carriers, destroyers, frigates) to preserve shipping lanes. This demonstrates how a relatively small paramilitary group can shape global trade through intimidation and selective targeting. (washingtoninstitute.org, linkedin.com)
2. Iranian Proxy Warfare
   The Houthis’ improved capabilities underscore Tehran’s growing proficiency in proxy conflict. Iranian-supplied Saegheh drones and modified Qased-2 missiles exhibit extended range (150–200 km) and advanced sensors, allowing strikes from deep within Yemen. The Chinese satellite imagery channel (CGSTL) further signals Beijing’s indirect facilitation of Houthi targeting—highlighting a tripartite antagonism to U.S. regional influence. (linkedin.com, wsj.com)
3. Resilience of Non-State Actors
   Despite sustained U.S. and U.K. airstrikes that inflicted heavy personnel and material losses (500–600 Houthi fighters killed between March and April 2025), Houthi launch sites remain dispersed and underground. The decentralized command structure and widespread use of cave complexes complicate targeting, making complete neutralization unlikely without a ground intervention—an option the U.S. and U.K. have explicitly ruled out. (en.wikipedia.org, janes.com)
4. Cost Imbalances and Sustainment Challenges
   Coalition air operations (~800 strikes) have successfully degraded some Houthi capabilities but at significant political and financial cost: extended deployments strained U.S. carrier groups, and attrition of multiple F/A-18 and F-35 jets reduced carrier strike availability. In contrast, Houthis incur minimal capital expenditures—most missiles and drones cost $20,000–$50,000 each—presenting a favorable cost-exchange ratio for the Houthis and their Iranian backers. (en.wikipedia.org, wsj.com)

Implications

• Global Trade Stability
  Although maritime traffic rebounded by 60 percent under EU escorts, full restoration remains elusive. Continued Houthi strikes against Israel-linked shipping can provoke broader regional escalations, compelling more costly detours, increasing insurance premiums, and sustaining consumer price inflation. (reuters.com, neptunep2pgroup.com)
• Regional Security Dynamics
  The conflict has drawn in multiple actors:
  • U.S. and U.K.: Committed to interdiction via airstrikes and maritime patrols, yet reluctant to deploy ground forces.
  • EU: Limited naval assets constrain escort frequency, risking a renewed decline in shipping if additional Houthi factions join.
  • Iran: Gains strategic leverage by demonstrating capacity to disrupt global commerce without overt state confrontation.
  • Saudi Arabia and UAE: Watching closely, as their own Red Sea coastlines and maritime commerce remain at risk, potentially motivating direct bilateral or multilateral initiatives to counter Houthi threats. (hntrbrk.com, wsj.com)
• U.S. Naval Readiness
  Extended deployments in the Red Sea and Gulf of Aden have diverted U.S. carrier strike groups from Indo-Pacific rotations, temporarily weakening deterrence posture vis-à-vis China. Drone losses (MQ-9 Reapers) and constraints on carrier air wings underscore the challenge of distributed lethality against swarming drone threats. (wsj.com)
• Non-State Actor Empowerment
  Houthi successes may embolden other non-state actors in the region (e.g., IRGC-affiliated militias in Iraq or Lebanon), fostering a norm where maritime interdiction becomes a state-sanctioned tactic to influence foreign policy. (washingtoninstitute.org, thesoufancenter.org)

Recommendations

1. Augment Coalition Naval Presence
   • Expand Escort Fleets: EU and U.S. partners should commit additional frigates and destroyers—possibly staffed by rotating crews—to maintain a persistent maritime security presence in the Bab al-Mandeb corridor. This would reduce gaps that Houthis exploit during escort transitions. (reuters.com, ship-technology.com)
   • Integrate Unmanned Surface Vessels (USVs): Deploy expendable USVs equipped with radar and missile-warning sensors to supplement manned escorts, offering early detection of incoming missiles or drones at lower risk and cost.
2. Enhance Shore-Based Strike Capabilities
   • Precision Rocket Artillery (PRA): Stage U.S. M142 HIMARS batteries on regional bases (e.g., Djibouti) with extended-range ATACMS missiles to rapidly engage Houthi launch sites in western Yemen. PRA can precisely target dispersed launch cells beyond the range of carrier-based aircraft, reducing reliance on costly airstrikes. (en.wikipedia.org)
   • Intelligence Fusion Centers: Establish a combined U.S.–U.K.–EU intelligence fusion cell in Bahrain to process real-time satellite, drone, and human-source data, expediting target identification and minimizing collateral damage.
3. Deny Houthi Access to Advanced Sensors
   • Sanction Satellite Imagery Providers: Impose secondary sanctions on entities like CGSTL that supply high-resolution imagery to Houthi forces, disrupting their targeting cycles. Promote alternative commercial imagery sources with embedded time-delay or degraded resolution in sensitive regions. (linkedin.com, hntrbrk.com)
   • Counter-Satellite Reconnaissance: Collaborate with partner nations to monitor potential liftings of imagery restrictions over the Red Sea and implement automated geofencing alerts for ships in transit, notifying escorts of unusual sensor activity.
4. Strengthen Regional Partnerships
   • Gulf Cooperation Council (GCC) Collaboration: Engage Saudi Arabia, UAE, and Egypt in joint maritime patrols, leveraging their proximity to the Red Sea. Offer security assistance to enhance their coast guard and naval capabilities for independent escort missions.
   • East African Naval Capacity Building: Provide Kenya, Djibouti, and Somalia with radar stations and fast patrol craft to monitor southern approaches to the Bab al-Mandeb, relaying threat data to coalition command centers.
5. Counter Houthi Propaganda and Recruitment
   • Information Operations (IO): Launch targeted IO campaigns emphasizing civilian harm caused by Houthi attacks—highlighting local Yemeni economic disruptions—to erode grassroots support. Utilize Arabic-language broadcasts and social media to showcase humanitarian aid for communities damaged by coalition strikes.
   • Interdict Financial Flows: Collaborate with financial intelligence units (FIUs) to trace and freeze assets linked to Houthi leadership networks, cutting off revenue streams used to procure weapons.

Conclusion

The ongoing Houthi maritime campaign demonstrates how a non-state actor, with state sponsorship, can significantly disrupt global trade routes and compel major powers to allocate disproportionate resources. Despite robust coalition efforts—over 800 airstrikes and 476 escorted vessels—Houthi-aligned groups continue targeting Israeli and U.S. interests in the Red Sea. A May 6, 2025 cease-fire reduced attacks on U.S. vessels but left Houthi threats to Israeli-linked shipping unresolved. Without bolstered coalition naval presence, enhanced shore-based strike options, and measures to deny advanced targeting data, the Red Sea remains vulnerable to renewed or expanded Houthi aggression. Strengthening regional partnerships and countering Houthi propaganda are also essential to reduce local support for maritime attacks. Persistent, coordinated efforts across diplomatic, military, and informational domains will be required to restore sustained maritime security in this critical chokepoint.