CNN –
U.S. warships in the Red Sea have been battling a growing number of weapons fired by Houthi forces in Yemen in recent weeks, including an incident on Saturday in which a U.S. destroyer shot down more than a dozen drones.
And confrontations between the U.S. and the Houthis, who say they are targeting merchant ships bound for Israel after the invasion of Gaza, may increase after Defense Secretary Lloyd Austin announced a new U.S.-led operation on Monday, which focuses on protecting merchant ships operating in the Red Sea and the Gulf of Aden.
In light of recent US naval actions and the announcement of the new US protection initiative, CNN interviewed naval experts about how warships are dealing with the threats and what problems they might face in the future.
The U.S. Navy has not said what weapons systems its ships are using to combat the Houthi attacks, but the experts said a U.S. destroyer has a range of weapons systems.
These include surface-to-air missiles, high-explosive shells from the destroyer's 5-inch main gun and close-in weapon systems, the experts said. They also said U.S. ships have electronic warfare capabilities that could disrupt the connection between drones and their controllers on land.
Whatever systems U.S. destroyer captains use, they face decisions about cost, inventory and effectiveness as the mission grows, the experts said.
“The drones are slower and can be hit with the cheaper missiles or even the ship's cannon. Faster missiles need to be intercepted with more complex interceptor missiles,” said John Bradford, senior fellow at the S. Rajaratman School of International Studies in Singapore.
Iran-backed Houthi forces have carried out numerous attacks against US interests in the region and against Israel since the Hamas attacks in Israel on October 7, as fears continue to rise in the region that the war between Israel and Hamas is expanding could.
The group said any ship heading to Israel was a “legitimate target” as it pressured Israel to halt its Gaza offensive. They have carried out several drone and missile attacks on merchant ships and even attempted to land commandos with helicopters on a ship to hijack it.
03:27 – Source: CNN
BP is the latest company to temporarily halt shipping due to attacks in the Red Sea
The world's largest container shipping companies have disrupted transit through one of the world's trade arteries, which experts say could cripple supply chains and drive up freight costs.
MSC, Maersk, CMA CGM and Hapag-Lloyd all said in recent days that they would avoid the Suez Canal for safety reasons. Oil giant BP followed suit, causing oil and gas prices to rise on Monday.
“This is one of the most important arteries in the world when it comes to maritime shipping,” former CIA Director David Petraeus told “CNN This Morning,” adding that the time and cost of transporting goods across Africa will be significant . “This will actually have a real impact on the global economy.”
The most important asset of the US Navy – the guided missile destroyer
According to its own statements, the US Navy wants to use the attacks to help merchant shipping that is in trouble.
The main US deployment in the Red Sea to counter attacks on shipping is the Arleigh Burke-class guided-missile destroyer, such as the USS Carney, which shot down the 14 Houthi drones on Saturday. The missiles in his magazine include:
– The Standard Missile-6 (SM-6), an advanced weapon capable of firing ballistic missiles high in the atmosphere and other lower-trajectory missiles and attacking other ships at a range of up to 370 kilometers, according to the Missile Defense Project the Center for Strategic and International Studies (CSIS). These cost more than $4 million each.
– The Standard Missile-2 (SM-2), less advanced than the SM-6 with a shorter range of 185 to 370 kilometers, depending on the version, according to CSIS. They cost about $2.5 million each.
– The Evolved Sea Sparrow Missile (ESSM), designed to hit anti-ship cruise missiles and slower threats such as drones or helicopters from up to 50 kilometers away, according to CSIS. Each one costs more than $1 million.
Experts assume that the USA is currently using SM-2 and/or ESSM missiles against the Houthi threat.
Expensive ammunition and the cost-benefit ratio
But because these are drones that can be manufactured and deployed in large numbers at prices under $100,000 each, a prolonged campaign could ultimately strain U.S. resources, the experts say.
“These are advanced air interception capabilities with an average cost of about $2 million – which makes drone interception not … cost-effective,” said Alessio Patalano, professor of war and strategy at King's College London.
The Houthi troops are financed and trained by Iran and therefore have the resources for a longer fight, the experts emphasize.
The question also arises as to how far the US wants to go to protect merchant shipping, the experts said.
01:03 – Source: CNN
'As if the gloves were off': Military analyst reacts after ballistic missiles are fired at a US warship
A U.S. destroyer's Phalanx close-combat weapons system – Gatling guns capable of firing up to 4,500 rounds per minute – could defeat drone or missile threats that come within a mile of the warship, said Carl Schuster, a former U.S. Navy captain and former director of operations at the U.S. Pacific Command's Joint Intelligence Center in Hawaii.
This is a relatively inexpensive defense. However, when drones get this close, it is the last line of defense and a miss could cost the US lives.
“A single missile or drone will not sink a U.S. warship, but it can kill people and/or cause damage that requires the ship to be withdrawn to port for repairs,” Bradford said.
And the Phalanx system cannot protect merchant ships that the U.S. destroyer may be watching over and that are miles away from the warship.
“To provide long-range air defense (as opposed to self-defense), ships rely primarily on anti-aircraft missiles,” said Sidharth Kaushal, a research fellow in maritime power at the Royal United Services Institute in London.
Kaushal said US anti-aircraft missiles on US warships were fired from Vertical Launch System (VLS) cells on the deck.
Each cell can contain a mix of weapons (exact numbers are classified), but the number on board a ship is limited, Kaushal said.
And if the Houthis manage to deplete a ship's supplies through back-to-back attacks, the warship could lack the ammunition to protect the merchant vessels it monitors, said Salvatore Mercogliano, a naval expert and professor at Campbell University in North Carolina.
02:30 – Source: CNN
The video shows the moment Houthi rebels storm a cargo ship in the Red Sea
“While the Navy is well equipped to deter what the Houthis are currently throwing, there are fears that the scope and scale will increase and escorts will not be able to maintain the level of defense to protect commercial shipping,” he said.
The Houthis have not yet attempted a true drone swarm attack – similar to the one Russia has repeatedly used in Ukraine – that could target dozens of incoming threats at once, the experts said.
“A swarm could test the capabilities of a single warship, but more importantly, it could mean weapons can get past it and hit merchant ships,” Mercogliano said.
US warships also face the question of how to replenish the region's missile inventory, he said.
“The only place where weapons can be reloaded is Djibouti (a US base in the Horn of Africa) and that is close to where this happened,” he said.
Patalano said the U.S.-led operation to increase the number of warships to protect merchant vessels will support defense efforts.
At a virtual ministerial meeting on Tuesday to discuss maritime security in the Red Sea with representatives from 42 other countries, Defense Secretary Austin said: “These reckless Houthi attacks are a serious international problem … and they require a decisive international response.”
Check out this interactive content on CNN.com
“These attacks threaten the free flow of trade and endanger innocent seafarers. They have to stop,” he added.
A day earlier, Austin announced the establishment of Operation Prosperity Guardian in the Red Sea, a multinational operation also involving the United Kingdom, Bahrain, Canada, France, Italy, the Netherlands, Norway, Seychelles and Spain.
“It appears that more ships will be able to support each other, de facto expanding the range and scope of capabilities available in the region to address the challenge,” Patalano said.
While increased cooperation among allies could help, the experts said the use of anti-ship cruise missiles or ballistic missiles could pose a new challenge.
Anti-ship cruise missiles “can fly low and penetrate the hull of a ship above the waterline. “This is the type of weapon that sank several British ships during the Falklands War and hit the USS Stark (in the Persian Gulf) in 1987,” Mercogliano said.
Ballistic missiles could pose an even greater threat, he said.
“The terminal velocity of the weapon and its payload could cause serious damage to a warship or merchant vessel,” he said, and it may take the best U.S. interceptors like the SM-6 to shoot it down.
Mercogliano said the battlefield is not static and the Houthis will have some say in what they will use.
“The Houthis are watching and seeing how the Navy responds to these attacks,” he said.
And the experts say that at some point the US may decide to go on the offensive.
“There is another approach that stands out at the source. This would shift the focus from intercepting capabilities once they are airborne to attacking them at the source to prevent their use in the first place,” Patalano said.
“If you have choice and skill, it is always cheaper to take out the archers than to intercept the arrows,” Schuster said.