How Saudi Arabia and the UAE’s long alliance ruptured

It was a covert military shipment docking at a Yemeni port that finally brought simmering tensions between Gulf heavyweights Saudi Arabia and the United Arab Emirates dramatically into the open.

Riyadh had for weeks been unsuccessfully using diplomatic channels to pressure a UAE-backed Yemeni faction to withdraw from provinces it had seized next to the Saudi border in December. Now, Saudi Arabia alleged, the UAE was shipping weapons and armoured vehicles to the group, the separatist Southern Transitional Council.

Riyadh was infuriated. It bombed the shipment, publicly accused the UAE of supporting the Yemeni faction’s offensive and called for Abu Dhabi to pull its remaining troops from the war-torn state. The UAE rejected the Saudi allegations but said it would withdraw its forces as it sought to de-escalate the crisis.

The extraordinary escalation plunged the Saudi-backed Yemeni government into chaos. But its repercussions could be felt far wider, pitting key US allies, major trading partners and the Arab world’s two most influential leaders against each other: Saudi Crown Prince Mohammed bin Salman, known as MBS, and UAE President Sheikh Mohamed bin Zayed al-Nahyan, or MBZ.

“It’s worrying because it compromises efforts to address every point of tension in the region — Yemen, Gaza, Syria, Lebanon and Sudan,” said Dan Shapiro, a former US diplomat now at the Atlantic Council. “Each of those will be harder to solve if Saudi Arabia and the UAE are not on the same page and see their interests in conflict.”

A decade ago, the two Gulf states’ long alliance seemed destined for an energising new chapter between ambitious leaders.

MBZ, who at 64 is more than two decades older than MBS, was an early backer of his Saudi counterpart’s drive to modernise and promote a more moderate version of Islam in the deeply conservative kingdom.

The UAE had long profited from acting as a base for foreign companies doing business in Saudi Arabia, the world’s top oil exporter and the Gulf’s largest economy. But Abu Dhabi was wary of the social and political risks of the conservative nation on its doorstep stagnating. Attempts at reform were welcomed.

As their relationship blossomed, MBZ promoted MBS and his plans in Washington. Some analysts suggested the older, more experienced Emirati acted as the millennial prince’s mentor — a characterisation dismissed in Riyadh.

In the region, they joined forces to assert power: the UAE was Riyadh’s main partner when MBS led a coalition to intervene against the Iran-backed Houthis in Yemen’s civil war in 2015. They also spearheaded a regional embargo imposed on Qatar in 2017 — which triggered the last Gulf crisis.

But as MBS became more confident and consolidated his power, he sought to propel his nation into what he believed was its rightful role on the global stage — and friction between the two assertive, absolute monarchies resurfaced.

“Each saw itself as the natural leader: Saudi believes its size and symbolic power should prevail, while the UAE believes its trailblazing power is more in sync with global dynamics,” said Emile Hokayem at the International Institute for Strategic Studies.

Under MBZ, the UAE used its financial clout and relationships in the west to become arguably the most influential Arab state, despite its small size. After the 2011 popular uprisings threatened the status quo in the Middle East, the UAE became the most assertive regional actor as it sought to push back against Islamist movements and shape the region in its vision.

Hokayem said Saudi Arabia and the smaller, agile UAE “have very different risk profiles, domestically and globally, and different views of how the region should be structured”.

Tensions first surfaced in Yemen in 2019 when the UAE shifted policy and announced it would withdraw its troops, which were the Saudi-led coalition’s main foreign force on the ground. The same year, the Saudi-backed Yemeni government accused the UAE of bombing its forces as the Gulf states backed competing anti-Houthi factions.

Economic rivalry also intensified, reaching a high in 2021 when MBS launched a campaign to coerce multinationals to move their regional headquarters from the UAE to Riyadh. Corporates were given three years to make the move or risk losing out on lucrative government contracts. Emiratis viewed the move as a direct challenge to Dubai’s role as the region’s leading finance hub.

Differences have also festered over Syria, the Sudanese civil war and crude production quotas determined by Opec+ — the oil cartel of which Saudi Arabia is the de facto leader.

As tensions ebbed and flowed, Sheikh Tahnoon bin Zayed al-Nahyan, the UAE’s national security adviser and MBZ’s brother, would be dispatched to Riyadh to smooth over their differences.

Considered less ideological than MBZ, Sheikh Tahnoon has good relations with the Saudis. But as the gaps between Riyadh and Abu Dhabi widened and the power dynamics shifted, his task became harder, a former US official said.

“Tahnoon used to go regularly to Saudi Arabia to tend the grass, and the worse things were, the longer he would stay,” the former official said. “Now MBS is king in all but name, it’s affected Tahnoon’s ability to do his relationship mending.”

Analysts say the Gulf states still have more in common than not, and both sides talk of their “brotherly” neighbours. But in recent months, the war in Sudan has put them at odds.

Both had backed the Sudanese military leadership that took over after Omar al-Bashir was ousted in 2019. But when the Sudanese Armed Forces (SAF) and the Rapid Support Forces (RSF) paramilitary turned their guns on each other, differences emerged between the Gulf nations.

Riyadh is closer to the SAF, which it sees as representing the state, but the UAE thinks it is infiltrated by Islamists. Abu Dhabi is alleged to have instead supplied weapons to the RSF, which has faced accusations of genocide. The UAE denies arming the militia.

MBS voiced his concerns about the Sudan conflict and the RSF with Donald Trump during a White House visit in November.

Soon after the Trump-MBS meeting, the latest Yemen crisis erupted. In December, the UAE-backed STC faction — which is ostensibly part of the Yemeni government — seized control of the two provinces by Saudi borders, Hadhramaut and al-Mahra.

Riyadh believes Abu Dhabi wrongly thought that MBS raised the issue of sanctioning the UAE, and then greenlit the STC’s advance out of anger with the kingdom.

Abdulkhaleq Abdulla, an Emirati academic, said linking the events in Yemen to differences over Sudan was “wild analysis”.

The conflict in Yemen had stagnated after Riyadh agreed to a truce with the Houthis in 2022 and sought to extract itself from the war, with MBS focusing on his domestic agenda.

But the separatist offensive dealt a severe blow to Saudi Arabia’s influence, as well as the Yemeni government it backs. And, in Riyadh’s thinking, it impinged on its national security.

“Yemen is Saudi Arabia’s backyard,” said Firas Maksad, managing director for the Middle East and north Africa at Eurasia Group. “The offensive launched by UAE-backed forces . . . crossed Saudi redlines.”

Maksad said Abu Dhabi’s decision to withdraw its remaining forces provided an “off-ramp from what otherwise would be a head-on collision with significant fallout”.

However, the risk, Maksad said, is that the crisis “could transform Saudi-UAE geopolitical competition to a personal showdown between the region’s leading strongmen”.