Shortly before midnight on Monday, Saudi Arabia issued an evacuation notice over state channels, tel...Show more

Shortly before midnight on Monday, Saudi Arabia issued an evacuation notice over state channels, telling civilians to clear the area around the port of Mukalla. The kingdom had decided that whatever was coming ashore in Yemen's east was an “imminent threat”. A few hours later, armoured vehicles were rolling down a ship's ramp. According to Saudi and Yemeni officials, two vessels had arrived in Mukalla from Fujairah on the Emirati coast and switched off their tracking systems before unloading combat vehicles and weapons intended for the Southern Transitional Council (STC), the UAE-backed separatist movement that has spent the past month widening its grip across southern Yemen. At dawn on 30 December, Saudi aircraft struck the port in what Riyadh called a “limited” operation, tight enough to avoid mass casualties, loud enough to be heard in Abu Dhabi. Yemeni state media showed smoke rising above the docks, and burned-out vehicles near the waterfront. The head of Yemen's Presidential Leadership Council (PLC), Rashad al-Alimi, responded with a demand that Emirati forces leave Yemen within 24 hours. He also cancelled a defence pact with the UAE and imposed emergency restrictions on ports and crossings. Saudi Arabia, for its part, chose words it has largely avoided in public when speaking about a fellow Gulf state: its national security was a “red line”, and the Emirati steps were “extremely dangerous”. Hours after the Saudi strike, the UAE announced that it will withdraw its military personnel from Yemen and “the termination of the remaining counterterrorism personnel of its own volition”. Despite the Emirati decision, which is more tactical than strategic, this was not, at its core, a quarrel about a single consignment. It was the clearest sign yet that Saudi red lines in Yemen have been crossed, and that the kingdom's patience, after a decade of grinding war and uneasy compromise, is running out. To understand why Riyadh took the extraordinary step of striking a port that has sat for years within the anti-Houthi camp, one has to look past the pier and into two competing Gulf visions for Yemen. Saudi Arabia's Yemen policy has, in recent years, been shaped as much by trauma as by strategy. The military campaign launched in 2015 became a costly lesson in the limits of Saudi coercion. Crown Prince Mohammed bin Salman has since worked to recast Saudi Arabia as a power that buys stability with diplomacy, investment and regional deconfliction, ending the Qatar blockade in 2021 and restoring ties with Iran in 2023 as part of a broader effort to lower the regional temperature, enabling the kingdom to focus on its domestic economic transformation. In Yemen, that shift has meant restraint and engagement. Riyadh has leaned on Muscat to keep a channel open to the Houthis, betting that Oman's reputation as a quiet broker can help turn a ceasefire into a political track that allows Saudi Arabia to step back, without watching Yemen collapse into an even worse security threat on its southern border. For Riyadh, unlike for Abu Dhabi, Yemen is not a chessboard, but its backyard. In 2022, Saudi sponsorship of the PLC was supposed to serve the same purpose on the anti-Houthi side. The kingdom wanted to create an umbrella structure that could corral fractious Yemeni factions into something resembling a state, or at least a negotiating counterpart. Saudi interests in Yemen have always been non-negotiable. The kingdom can live with an imperfect settlement, yet it cannot live with a hostile or ungoverned belt along its border, nor with a Yemen carved into rival fiefdoms where missiles, drones and smugglers move freely. The UAE's strategic culture is different, and so are its overall objectives. Abu Dhabi has built a regional role by being nimble, networked and relentlessly transactional. Through its “axis of secessionists”, Abu Dhabi has cultivated networks of partners that are the polar opposite of the hierarchical structures of its Gulf neighbours: militias, mercenaries, private intermediaries and financiers, local strongmen, logistics companies and commodity traders. It wraps much of this in the language of fighting political Islam, but the map of Emirati activism is unmistakably geo-economic: it is about chokepoints, logistics hubs, resources and trade corridors. In Yemen, that approach has long centred on the south. The STC was not simply “backed” by the UAE; it was nurtured into an ecosystem consisting of a political leadership, security forces and patronage networks that could function as a quasi-state, all wrapped in a powerful, organic southern separatist narrative. This month's offensive, in which the STC and aligned forces seized key ground in Hadhramout and pushed the Saudi-backed PLC government further towards irrelevance, has turned that long-running project into a fait accompli. For Saudi Arabia, this is the moment when quiet discomfort became an acute strategic problem. The kingdom is now staring at what many Yemenis have feared for years: not one Yemen, but “two and a half” Yemens, a Houthi north, an STC-dominated south, and a nominal government in the middle that exists more in conference rooms than in territory. The strike on Mukalla was Riyadh's way of saying it will not accept a separatist arc stretching towards the very maritime corridors that define Yemen's geopolitical weight. Mukalla matters because Hadhramout matters. It is not only Yemen's largest governorate; it is also the eastern hinge between the Gulf and the Arabian interior, bordering Saudi Arabia and carrying deep social and historical ties with the kingdom. And in a year when Houthi attacks have repeatedly exposed the fragility of Red Sea shipping, Saudi decision-makers are newly sensitive to any actor that could weaponize Yemen's coastline, ports and access routes, whether that actor is an Iranian-aligned movement in Sanaa, or a UAE-aligned separatist authority in the south. The immediate risk is that a coalition that once presented itself as a united front against the Houthis is now splintering into open confrontation, as Abu Dhabi and Riyadh find themselves increasingly on opposite sides in Sudan, Palestine and Somalia as well. The less obvious risk is that the UAE's model of network-centric statecraft makes Saudi ultimatums easier to issue than to enforce. Abu Dhabi may not need large, uniformed deployments to retain influence; it can delegate and embed. Asking “Emirati forces” to leave Yemen might be symbolically potent, but it will leave intact the local structures Abu Dhabi has built, and these are the ones that matter most. So the announcement by the UAE to withdraw all its forces from Yemen, the second such announcement since 2019, has to be understood in the context of Emirati doublespeak. Mukalla should thus be read less as a tactical strike than as a strategic message. Saudi Arabia is signalling that, having tried accommodation, it is prepared to reintroduce calibrated coercion to defend its core interests, even, or especially, against the UAE. It is also signalling that it believes Abu Dhabi responds to pressure more than persuasion. Yet pressure alone is not a Yemen policy. If Saudi Arabia and the UAE continue down this path, they will do what Yemeni actors have done for a decade: make the Houthis stronger by dividing everyone else. Riyadh has to act more confidently, relying on the consensual and coercive levers at its disposal. The kingdom still has tools Abu Dhabi values: airspace control, diplomatic cover and the convening power that comes from being the region's central economic prize. It can also use them to insist on three principles: no unauthorised military supply lines into Yemeni ports, no unilateral territorial changes by coalition-aligned factions, and a political track that absorbs legitimate southern grievances without converting them into an externally armed secession project. Mukalla marks a sea change. Saudi Arabia has fired what amounts to a warning shot across an ally's bow: the era in which the UAE could build a separate sphere of influence inside Yemen, while sheltering beneath the label of a “Saudi-led coalition”, is ending. The question now is whether Abu Dhabi hears it as a moment to negotiate boundaries, or as the ongoing round of a new contest along the very shores that the world, in an age of fragile trade routes, can least afford to see burn. Show less