In the sterile, high-altitude boardrooms of the Gulf, the mantra for the last decade has been one of shared destiny. From the 2017 blockade of Qatar to the initial intervention in Yemen, Riyadh and Abu Dhabi appeared to be the twin engines of a new, assertive Arab order. Yet, as 2026 begins, that veneer of unity has not just cracked; it has been replaced by a series of high-stakes jurisdictional disputes stretching from the mountains of southern Yemen to the ports of the Horn of Africa.

The most dramatic evidence of this shift arrived in the closing days of 2025. On December 30, the Saudi Air Force conducted a rare and pointed strike on the Yemeni port of Mukalla. The target was not the Houthi rebels, but a shipment of armored vehicles and weaponry allegedly destined for the Southern Transitional Council (STC), the separatist movement backed by the United Arab Emirates. For Riyadh, this was a “red line” moment. For Abu Dhabi, it was a “blatant military assault” on a partner.

To understand this friction, one must look beyond mere personality clashes between Crown Prince Mohammed bin Salman and President Sheikh Mohamed bin Zayed. The divergence is structural. Saudi Arabia, as the traditional regional heavyweight with a long land border with Yemen, remains committed to the principle of state sovereignty and territorial integrity. Riyadh views a unified,........

© Middle East Monitor