The Iran-aligned group has demanded that Israel allow humanitarian aid to enter Gaza, which has been reeling from more than two months of Israeli siege and bombardment. The Yemeni group has also called on Israel to end its brutal war on Gaza that has killed over 19,000 Palestinians.

The United States on Tuesday announced the formation of a 10-nation coalition to deter the attacks that threaten to disrupt trade passing through one of the busiest maritime routes in the world.

Let’s take a look at who the Houthis are, just how much they are disrupting global trade, and what they can hope to achieve from it.

Who are the Houthis?

The Houthis rebelled against Yemen’s internationally recognised government in 2014, starting fighting that led to a civil war that caused a devastating humanitarian crisis in the impoverished Arab nation.

For years, with backing from Iran, they fought a military coalition led by neighbouring Saudi Arabia that also included Western and regional allies. However, the Yemeni conflict became a stalemate, with Saudi Arabia deciding to begin peace talks with the group after years of war.

Also known as Ansar Allah, they now remain in control of most parts of Yemen, including the capital Sanaa and some of the western and northern parts close to Saudi Arabia.

They command a considerable military arsenal, which includes a variety of drones and missiles – including ballistic antiship missiles that they have for the first time ever successfully used against vessels in the Red Sea.

Earlier this year, Saudi Arabia agreed with Tehran, a close Houthi ally, to restore formal diplomatic ties after a seven-year rift.

With the Yemeni talks and Iran rapprochement hanging in the balance, the kingdom has not joined the US-led military alliance. Other Arab heavyweights like the United Arab Emirates and Egypt have not joined either.

Who are they attacking?

The Houthis first launched missiles and drones at southern Israel in October, but they either did not reach their far-away targets – some 2,000km (1,240 miles) away – or were intercepted by Israel and its allies.

But as Tel Aviv kept refusing international calls for a ceasefire, they significantly ramped up their strikes, leveraging their position near the Red Sea, and especially close to the narrow Bab al-Mandeb Strait that connects the Gulf of Aden to the southern part of the sea.

They have seized and kept in their ports a commercial vessel, they have attacked several more trade ships carrying everything from vehicles to foodstuffs, and the Pentagon claims some of their projectiles were travelling in the direction of US warships before being shot down.

The Houthis have said ships with no links with Israel will have nothing to worry about, and they will only target vessels owned by Israel or taking goods to and from Israel. But tracking ownership of ships can be difficult, and some targeted companies have denied having ties with Israel.

How seriously are they disrupting trade?

The Bab al-Mandeb is where 12 percent of the total global seaborne trade of oil, as well as 8 percent of liquified natural gas, passed through in the first half of 2023, according to the US Energy Information Administration. That is 8.8 million barrels per day of oil and 4.1 billion cubic feet per day of LNG.

More than 17,000 ships pass through it each year, some heading to the Suez Canal that takes them to the Mediterranean and acts as the link between Asia and the West.

Denmark’s AP Moller-Maersk, which accounts for 15 percent of the global container freight market, has been among several of the largest global names in the shipping industry to opt out of taking the route. Together with Germany’s Hapag-Lloyd, which has also pulled out, they account for almost a quarter of the market.

Container rates for shipments from North Asia to the United Kingdom, which go through the Red Sea and Suez Canal, have hit record highs this year, according to assessments by S&P Global Platts. Underwriters are charging more to insure ships planning to take the route as well.

Some shipping companies are choosing the only other maritime alternative – to take a much longer route around Africa. But that can mean increased costs, and it can add up to two weeks to their journey.

The complications for shipping companies come amid another unfortunate incident for them as the vital Panama Canal has also faced a sharp decrease in the traffic it can handle due to drought.

Who could get affected the worst?

Israel, the first direct intended target of the Houthis, has already felt an impact from the disrupted maritime trade.

Traffic through its southern port of Eilat, located in the city which is also a tourist destination, has come to a halt, and the foreseeable future seems uncertain as the war rages.

Egypt, which was already facing an ailing economy before the war, could suffer heavily from the slowed trade, in addition to decreased transit fees for cargo going through the Suez Canal, something it is highly dependent on.

Europe and states in the Mediterranean are poised to suffer the most losses if the current situation persists in the long term, as many of the ships taking cargo to and from those countries have been affected.

What do the Houthis stand to gain?

The Houthis have steadily consolidated their power within Yemen over the years.

It was inevitable for them to wish to secure recognition from the international community as the legitimate government in Yemen as well, according to Thomas Juneau, an assistant professor at the Graduate School of Public and International Affairs at the University of Ottawa.

“They will not obtain that for the foreseeable future, but at the very least they want to force the international community to deal with them as the de facto governing authority in the country,” he told Al Jazeera.

“In the context of the Gaza war, they want to demonstrate that they are a key member of the Iran-led ‘axis of resistance’ by showing their support for Hamas. As such, I expect their efforts to disrupt maritime traffic in the Red Sea to continue.”

For their part, the Houthis have promised that the US-led task force will not deter them and they are capable of turning the Red Sea into a “graveyard”.