what happened?
In December 2025, events in Yemen exposed long-suppressed strategic differences between Saudi Arabia and the UAE. Formed in 2015 under the banner of “restoring the legitimate Yemeni government” and countering the Houthis, the Arab Coalition began as a joint security intervention, but by 2025 had evolved into an increasingly covert power struggle. Differences in goals, measures, and priorities within the coalition became particularly pronounced after 2018, and December 2025 marked a turning point when these differences were formalized.
Saudi airstrikes targeting Southern Transitional Council (STC) members in Mukalla, Hadramut, and Mehri from December 26 to 31, 2025 crystallized this rift. Riyadh has created a situation unprecedented in the coalition’s history by targeting forces that are its de facto partners, which the UAE has trained and supported. As a result, Yemen has become a conflict zone where actors within the same alliance use force against each other.
Hadramut and Mehri played a central role in this new phase. These two eastern provinces have long been relatively uninvolved in direct conflict with the Houthis, but have now become the main testing ground for conflicts within the coalition. The expansion of the STC into these provinces strengthened its control over South Yemen by early December 2025, but Saudi Arabia recognized that it had crossed a red line that should not be crossed. In an article for The Conversation, Gulf expert Christian Coates Ulriksen said the timing of the move, which coincided with the Gulf Cooperation Council (GCC) summit, strengthened Riyadh’s confidence that Abu Dhabi was aware of and approved of the move.
This crisis once again confirms that divisions within the Union are not new. Clashes in Aden in 2018 between UAE-backed Security Belt forces and Yemeni government forces were the first serious test of the coalition’s cohesion. In 2019, Riyadh interpreted the reduction of the UAE’s military presence and the continued influence of local armed groups as an Emirati abandonment of Saudi Arabia. Betul Doan Akkas of Ankara University describes this process as a “buckpassing” approach in an article for Anadolu Agency.
According to this approach, the UAE would have remained part of the coalition, but would have shifted most of the political and military costs of its intervention in Yemen to Saudi Arabia. The Riyadh Agreement signed in the same year and the Presidential Council established in 2022 were agreements that masked, but did not eliminate, this structural division. The shift of competition to eastern states in 2023 and 2024 sets the stage for a process that will culminate in December 2025, when the coalition becomes effectively dysfunctional.
