US and UK air strikes have reduced the risk to vessels from attacks by Yemen’s Houthis in the Red Sea but there is little prospect of many shipping companies making a swift return to the Suez Canal, security experts and a senior executive have said.

They made the assessment during a slowdown in successful missile launches by the Houthis, who claim to be targeting commercial ships in solidarity with Gaza’s Palestinians.

The militant group has launched only four notable attacks on vessels since January 26 — one on January 31, two on February 6 and one on February 12. In all but the most recent attack, the missiles failed even to hit the vessel.

The frequency of Houthi attacks has fallen significantly since US and UK forces began nearly daily strikes on the group’s missile launch sites and aerial and sea drone capabilities on January 11.

The Houthis, who have backing from Iran, launched numerous attacks in November, December and January, including seizing the Galaxy Leader on November 19 and taking the car carrier and its crew to a Yemeni port. On January 26, they started a serious fire on the Marlin Luanda, a fuel tanker operating on behalf of commodities trader Trafigura.

The recent lull prompted UK defence secretary Grant Shapps to tell the House of Commons last week that attacks on vessels had become “less sophisticated and more sporadic” following the bombing campaign.

However, the continued reluctance of many shipping companies to sail through waters off Yemen has raised questions about what change in conditions might prompt shipping companies to start braving the area, which is the gateway to the strategically vital Suez Canal.

They have instead been using the much longer and more expensive route between Europe and Asia via the Cape of Good Hope.

Jon Gahagan, president of maritime security company Sedna Global, said the campaign of air strikes seemed to have “degraded” the Houthis’ ability to launch frequent attacks.

But he added: “While the tempo of attacks has fallen, the threat to shipping remains.”

Jakob Larsen, head of maritime safety and security for Bimco, an international shipowners’ association, said he doubted it was “realistic” the US-UK coalition would entirely remove the Houthi threat.

“We’re concerned that it’s still possible for the Houthis to attack and hit ships,” Larsen said. “Although their capability to do so has been reduced, most shipping lines recognise that the threat has not been removed or neutralised.”

According to figures from Clarksons, the London-based maritime business, in the week to February 5, arrivals by container ships in the Gulf of Aden were 92 per cent down on the average for the first half of December.

Car carrier arrivals were down 91 per cent, while traffic overall through the region was down 73 per cent. The figures show no drift back towards the Red Sea.

Even the relatively modest recent attacks have prompted new diversions. France’s CMA CGM, the world’s third-largest container shipping line, announced on February 5 that it was suspending transits of the region after missiles were launched at a ship operating one of its services. The line had been one of the few big international container lines still sailing through the area.

The missiles landed harmlessly in the sea, as did those launched on February 6 at the Star Nasia, a carrier for dry bulk commodities. A missile launched on February 6 at the Morning Tide, a general cargo ship, flew over the ship’s deck but caused only minor damage. Reports on February 12 said missiles were fired at a Greek-owned bulk carrier in two separate incidents and that one hit.

Jan Rindbo, chief executive of Norden, a Copenhagen-based operator of nearly 500 dry bulk carriers and tankers for oil products, said only a long pause in attacks would prompt shipowners to re-examine Red Sea options.

“It would take a prolonged period of stability with no attacks in the region and then we’ll start to make those assessments again.”

Larsen pointed out that certain shipping companies were continuing to use the Suez route. Among the companies that have stuck to the traditional routes are some Chinese container lines, which appear to be confident the close links between China and the Houthis’ backers in Iran make them immune from attack.

“If the Houthis say they would no longer attack shipping, I think a lot of shipping lines will resume the transit through the Gulf of Aden and the Red Sea,” Larsen said.

Another possibility, he added, was that the attacks might cease, without a clear signal from the Houthis. “You’ll see more and ships transiting through, but a little later only,” Larsen said of such a scenario. “It will be a gradual increase.”

Gahagan, however, said the Houthis still wanted to strike international shipping, attributing the decline in attacks partly to a reduction in vessels with links to Israel, the UK and the US in waters off Yemen.

The risk remained that coalition forces would miss a Houthi missile fired at a ship and it would cause serious damage, he added.

“Unfortunately, as with all incidents of terrorism, the Houthis only have to be successful once, while the coalition naval force and other navies in the region have to be vigilant all the time,” Gahagan said.

Additional reporting by John Paul Rathbone