Houthi forces have captured the whole of Yemen’s Red Sea coastline, reaching all the way to the critically important Bab al-Mandeb shipping gateway, as the group’s rapid offensive continued on Friday.On Thursday, the Houthis seized the port city of Mocha, dealing a heavy blow to the Yemeni government backed by neighbouring Saudi Arabia.Recommended Stories list of 4 itemslist 1 of 4Oil soars to $109, pushing up chances of US interest rate increaselist 2 of 4Yemen war escalates: Who are the key actors involved?list 3 of 4Houthis advance along Yemen’s southern Red Sea coastlist 4 of 4Saudi political analyst says ‘No prolonged war with the Houthis’end of listAnalysts are calling the Iran-backed Houthi group’s victories the most significant regional development since the US and Israel declared war on Iran in February.The offensives could be particularly damaging for Saudi Arabia and its oil exports. The Houthis, who declared a blockade of Saudi-flagged ships in the Red Sea earlier in the year, now have a much firmer control of the Bab al-Mandeb waterway, which Riyadh increasingly relies on for oil exports following blockades of the the Strait of Hormuz at the entrance to the Gulf, experts say.But can the Houthis control the Red Sea?Here’s what we know:A satellite image obtained by Reuters on September 8, 2026 shows smoke rising from a Saudi Aramco distribution centre in Abha Bulk, after what the Saudi-led coalition in Yemen said were attacks by Yemen’s Iran-aligned Houthis [NASA/Handout via Reuters]What’s happening in Yemen?Yemen has been in a state of war since 2014 when Houthi rebels seized the capital Sanaa, as well as the port city of Hodeidah, forcing the government to step aside.With Iran’s backing, the group has since battled a Saudi-backed military coalition of Gulf states fighting on the side of the internationally recognised government of Yemen based in Aden.Saudi Arabia entered the war in 2015 in a bid to restore the Yemeni government and counter Iran’s expanding influence.Although a UN truce in 2022 halted fighting, intermittent clashes have occurred since then. A new wave of fighting resumed last week – among the most intense in years – as the Houthis attacked positions with the aim of seizing the Red Sea coast. Yemeni government forces struck back.In July, amidst the US-Israel war on Iran, the Houthis announced a complete maritime blockade on Saudi Arabia and began launching attacks on Saudi-linked ships passing through the important Bab al-Mandeb Strait.The narrow strait is one of the world’s most important shipping lanes connecting the Suez Canal and Red Sea to the Gulf of Aden. Roughly 12 percent of global trade passes through daily.Even more vessels have used it since Iran’s closure of the Strait of Hormuz, through which about 20 percent of the world’s energy supplies used to transit annually before the war began in February.What do Houthi gains mean for Saudi Arabia?The Houthis’ complete control of the Bab al-Mandeb corridor could worsen the ongoing global energy crisis as prices and supplies will increase, warn experts.For Saudi Arabia, it could further damage oil exports.Since Iran blockaded the Strait of Hormuz, Riyadh has sought to make greater use of its East-West Crude Oil Pipeline, which runs from the Abqaiq oil field across the vast Arabian Peninsula to the western port of Yanbu on the Red Sea. Oil can then be shipped via that sea route instead of the Gulf.The pipeline has been active since the 1980s and was purpose-built to avoid disruption in Hormuz. It was temporarily shut down during Houthi drone attacks in 2019.Since the February war, the kingdom has increased the pipeline to full capacity, meaning it can now pump up to seven million barrels per day (bpd) across the country to the Red Sea coast, up from five million bpd before the war. As a result, 21 percent more Saudi oil is being shipped through Bab al-Mandeb than before the US-Israeli war began.In response, the Houthis have targeted Saudi oil tankers in the Red Sea. But with the group now commanding the entire Yemeni coast and Bab al-Mandeb, Saudi exports could take a further hit.The Houthis have already targeted Saudi energy installations and southern cities. Images on Friday appeared to show smoke billowing from the East-West pipeline. The Saudis have not confirmed whether it was hit.What does this mean for Iran?Experts say the Houthis appear intent on opening up a new major front in the US-Iran war and, importantly, to hand Tehran a bingo card in its ongoing stalemate with Washington. Both Iran and the US claim to be in control of the Strait of Hormuz, but much reduced shipping volumes suggest Iran has the upper hand, observers say.Proxy control of the Bab al-Mandeb only strengthens that hand.“It essentially means Iran now controls the Strait of Hormuz and the Strait of Hormuz plus,” said Alam Saleh, professor of international relations at the Australian National University.It also increases pressure on Washington as surging petrol and food prices have already made the war highly unpopular, with voters expected to show their anger towards Republicans in the November mid-term elections. This week, President Donald Trump acknowledged that it is unlikely the war will end before then.While Washington calculates that a strategy of strikes combined with economic pressure could bend Tehran to its will, it is increasingly short on time to shift the situation in its favour, Saleh said.The Houthis’ victory not only significantly shifts the power balance in Iran’s favour, it also signals to other powers, such as China and Russia, that US military power in the Middle East is diminishing, he added.“Iran has now played the card of global oil prices and energy security. So the Houthis controlling Bab al-Mandeb benefits Iran dramatically.”Can the Houthis hold the Red Sea?Thursday’s defeat of Yemeni government forces was almost handed to the Houthis on a platter, analysts say.Yemeni government forces number an estimated 300,000, while the Houthis have about 250,000.However, internal fractures within the Yemeni military, as well as external pressure from Saudi Arabia, have created a highly fragmented front that lacks the cohesion needed to fight a group as quick and adaptable as the Houthis, experts say.“I would say that this is a fighting force that is probably more advanced than the force that the Saudis were fighting against about a decade ago,” Mohamad Elmasry, a professor at the Doha Institute for Graduate Studies, said of the Houthis.In addition, access to Iranian weapons in the past several years, ranging from missiles to drones to air defence systems, has enabled the Houthis to build an impressive stockpile, he added.However, Andreas Krieg, an associate professor at King’s College London, told Al Jazeera that despite their immediate victories, the Houthis are “terrible” at governance and are unlikely to sustain a blockade of Bab al-Mandeb. Their successful advance has happened not because they were underestimated, but because the Saudi-backed coalition was overestimated, he added.Still, Saleh of the ANU points out, the Houthis don’t actually need to control the whole of Bab al-Mandeb or the Red Sea to achieve their objectives. A hint of danger is enough to pressure shipping companies and insurance firms that the strait is too risky to enter, he said.The question now is whether Riyadh can effectively halt the Houthis with its own air power. In the past 24 hours, Saudi forces have launched dozens of missiles towards Houthi-controlled areas, including Mocha, but that has not appeared to have halted the group.A recent defence pact between Saudi Arabia, Pakistan and Turkiye is unlikely to kick in, say experts, as countries want to avoid an escalation in the US-Israel conflict with Iran.Washington seems unavailable too. US news site Axios reported that Saudi Crown Prince Mohammed bin Salman called US President Donald Trump twice on Thursday and requested American air strikes against the Houthis. Trump, however, declined.