The diplomatic veneer covering the rivalry between Gulf powerhouses Saudi Arabia and the United Arab Emirates has shattered, sparking fears of a chaotic proxy conflict that could destabilize the Red Sea corridor and the wider Horn of Africa.

Tensions reached a fever pitch this week after Saudi forces reportedly bombed vehicles docking at the Yemeni port of Mukalla—cargo that Riyadh alleges was military aid sent by the UAE to support southern separatists. For Kenya and its neighbors, this is not merely a distant desert squabble; a breakdown in Yemen threatens the vital shipping lanes that feed the port of Mombasa and risks pouring fuel on existing fires in Sudan and Somalia.

A Strike on Allies

The dispute centers on the United Arab Emirates' deepening support for the Southern Transitional Council (STC), a separatist group pushing for an independent state in South Yemen. While the UAE has long been a patron of the STC, Riyadh views the partition of Yemen as a direct threat to its southern border security.

In a move that stunned diplomatic observers, Saudi Arabia took direct military action against its nominal coalition partner. Riyadh confirmed the destruction of vehicles at Mukalla, pointedly noting they had arrived from an Emirati port. In a statement that abandoned diplomatic niceties, the Kingdom declared: “The kingdom stresses that any threat to its national security is a red line, and the kingdom will not hesitate to take all necessary steps and measures to confront and neutralise any such threat.”

Ripple Effects in the Horn

The fallout from this rupture is likely to wash up on East African shores. Both Saudi Arabia and the UAE are aggressive competitors for influence in the Horn of Africa, often backing opposing factions in regional disputes. Analysts warn that an open feud in Yemen could turn the Horn into a secondary theater for their rivalry.

The stakes for the region are high:

• Shipping Security: Yemen sits at the Bab el-Mandeb strait. Instability there threatens the trade route handling billions in goods destined for East Africa.
• Sudan Conflict: Both Gulf states have divergent interests in Sudan. A split in Yemen could lead to intensified proxy funding for warring generals in Khartoum.
• Commercial Access: The two nations are currently vying for control of African ports and logistics chains, a competition that could turn hostile.

The Independence Gamble

Diplomats in Riyadh had previously assumed the UAE—often viewed as the junior partner in the coalition—would pressure the STC to delay its independence bid. Instead, Abu Dhabi appears to have crossed Saudi red lines, emboldening the separatists to bypass the Presidential Leadership Council (PLC), the body recognized by the UN and backed by Saudi Arabia to unify the country.

If the STC proceeds with a declaration of independence, it could trigger a civil war within the south, pitting the separatists against Saudi-backed government forces. Such a conflict would leave the Iran-backed Houthis in the north as the primary beneficiaries of the chaos.

As the dust settles in Mukalla, the region holds its breath. If the two wealthiest Arab nations cannot reconcile their ambitions, the cost will be paid not just in Yemen, but potentially across the waters in an already fragile East Africa.