Royal Navy: HMS Diamond and Richmond operation to protect Red Sea from Houthis "not successful", report says

The International Institute for Strategic Studies Think Tank (IISS) has analysed the impact of Royal Navy and Allied missions fighting against Iranian-backed Houthi rebels. In a research paper titled Navigating Troubled Waters: The Houthis’ Campaign in the Red Sea and the Gulf of Aden, the think tank said although many lives were saved by UK and American intervention - under Operation Prosperity Guardian - it should not be deemed as successful due to persistent attacks throughout the year and shipping not returning to pre-militant levels.

Drones, missiles and other assets were used to target merchant vessels, with many of the assaults being blamed on goods being sent to Israel to support their operations in Gaza. HMS Diamond, a Portsmouth-based Type 45 destroyer, was deployed to the area - interchangeably with the Type 23 frigate HMS Richmond - in late 2023 and early 2024. The warship shot down multiple attack drones by deploying her Sea Viper missiles and guns in a co-ordinated defensive manoeuvre with American forces in January of this year.

She also shot down other drones in mid-December, and fired her missiles during other incidents in April. The Daily Express previously stated that it cost between £1m to £2m for every missile shot from the warship. The IISS said during Operation Prosperity Guardian - which had the aim of “ensuring freedom of navigation” and “bolstering regional security and prosperity” - 150 interceptions were made between November 2023 and August 2024.

Of the 309 weapons system targets involved, 229 of them were Uninhabited Aerial Vehicles (UAVs - primarily drones), 43 Uninhabited Surface Vessels (USVs), 30 ballistic missiles and others. The report said: “A number of attacks were thwarted, and the interceptions would have contributed to protecting freedom of navigation, as envisioned. However, the attacks have persisted at a consistent rate since interceptions began.”

“The total number of attacks per month barely declined, from 28 in December 2023 to 27 in August 2024, with higher counts in all other months within this period except July 2024,” the report added. “Therefore, Operation Prosperity Guardian and EUNAVFOR Aspides should not be judged as successful in this respect.”

Of the 292 total attempted attacks between November 2023 and August 2024, just 48 were successful - described by the report as “consistently low”. The paper added this could lead to the Houthis being unsuccessful, but some analysts suggest attacks without a clear target were simply a show of force and still had large global ramifications.

War risk insurance premiums rose for merchant ships, leading to thousands of them diverting around Africa. Despite this, the IICC said the global economic impact was milder than expected - with no significant rises in consumer costs and inflation as of early November 2024 - but has had a significant impact on Red Sea littoral nations.

Concluding remarks about Operation Prosperity Guardian said: “The defensive actions of Operation Prosperity Guardian and EUNAVFOR Aspides – while undoubtedly having saved the lives of civilian sailors – have failed to reassure the international shipping industry sufficiently for traffic in the Red Sea to return to pre-November 2023 levels.

“Mandated with protecting the freedom of navigation, the participating nations’ need to maintain significant naval assets in the region is a serious burden. This is particularly true for the EU and its member states, whose navies are already overstretched. Adding to this, the cost of depleting expensive weapons systems to defend against the more cheaply manufactured Houthi missiles and UAVs raises the question of how long the current missions can be sustained.”

They added: “One year after the start of the Houthi attacks, it seems clear that the current approach taken by the international community in addressing the challenge has failed to achieve its goal. Limited military action alone is not enough to reassure shipping lines sufficiently for traffic to return to pre-crisis levels.”