Defence Secretary Grant Shapps has said British forces are ready to act against Houthi rebels that target cargo ships in the Red Sea.
In a newspaper article, he said the UK was “willing to take direct action” to protect the key shipping lane.
Highlighting how a British warship shot down a suspected attack drone in the Red Sea in December, Mr Shapps said “we won’t hesitate to take further action”.
The Houthis have targeted foreign ships since the Israel-Hamas war started.
The Iran-backed rebel group has declared support for Hamas and has said it targets ships travelling to Israel, launching more than 100 drone and missile attacks.
The US and British warships have been shooting down these missiles and drones, at huge cost, but are now warning the Houthis to stop or risk military retaliation.
In his article in the Daily Telegraph, Mr Shapps wrote: “The Houthis should be under no misunderstanding: we are committed to holding malign actors accountable for unlawful seizures and attacks.”
He added: “Continued Red Sea aggression risks miscalculation and escalation which could trigger a region-wide conflict.”
If the Red Sea was not protected, he wrote, “it risks emboldening those looking to threaten elsewhere including in the South China Sea and Crimea”.
Mr Shapps said the situation was “a test for the international community” and that the UK needed to “stand firm with our allies”.
The US launched an international naval operation in December to protect ships in the area. Countries including the UK, Canada, France, Bahrain, Norway and Spain have joined.
As part of that alliance, HMS Diamond – a British Type 45 Destroyer – shot down a suspected attack drone that month. The Ministry of Defence said it was the first time in decades that the Royal Navy had shot an aerial target in anger.
Helicopters from nearby US warships responded to a distress call – and, after being fired upon, sank three boats “in self-defence”.
The crews were killed and the fourth boat fled the area.
The problem for the US, UK and their allies is that targeting the Houthis’ missile launch sites would seriously escalate the current crisis in the Middle East, potentially pulling the West and Iran into direct confrontation.
It would also portray the West – as viewed in the Arab world – as joining in the Gaza conflict on Israel’s side.
The Red Sea is one of the world’s most important shipping lanes as it links markets in Europe with Asia. Around 12% of global trade passes through the Bab El Mandeb Strait, near to where the Houthis are targeting shipping.
Analysts warn that the Houthi attacks could see a rise in prices, as it is also one of the most important routes for oil and liquefied natural gas shipments produced in the Middle East.