Saudi Arabia’s strike on Mukalla port has triggered tensions with its partner in the Arab coalition in Yemen and its Gulf Arab neighbour, the United Arab Emirates.

The coalition spokesman, Major-General Turki al-Maliki, said two ships entered the port of Mukalla, carrying more than 80 vehicles and containers of weapons and ammunition destined for the Southern Transitional Council (STC), without informing Saudi Arabia or the internationally recognised Yemeni government.

There are serious differences between the two allies in Yemen, and now it is at its peak and perhaps a turning point that would impact Yemen.

The Yemeni government has lost control of events following a military escalation between Saudi Arabia and the UAE in Hadramout governorate, where Mukalla lies, in December.

The Presidential Leadership Council (PLC) is divided into two factions, each loyal to one party in this conflict. The difference had been simmering for years away from the spotlight until it exploded publicly over the past few days.

Saudi Arabia and the UAE are key members of the Arab military coalition in Yemen, formed to confront the Houthis, who took full control of the capital, Sanaa, by force in 2015 and later imposed their own government.

This conflict of interest between Saudi Arabia and the UAE has been escalating gradually since the UAE-backed Southern Transitional Council (STC) formed in 2017 as a separatist political and military force seeking an independent state in the south – South Yemen – an independent state between 1967 and 1990.

Earlier in December, the STC forces crossed red lines by controlling all southern governorates, including Hadramout and al-Mahra governorates. That did not go down well in Saudi Arabia, which considered the move a threat to its national security.

Hadramout also represents economic depth for Yemen with its oil and gas resources and related infrastructure, and also has a vital border crossing with Saudi Arabia, making it part of the equation for border security and trade.

The latest public fallout between Saudi Arabia and the UAE will cast a dark shadow over the situation in Yemen politically, economically, and militarily. The Yemeni political circles were divided into two camps, with the government members each following one of the external parties to the conflict – Saudi and Emirati.

The clearest outcome of the differences would be seen in the eight-member PLC, an internationally recognised body, which is already divided into camps loyal to Saudi Arabia and the UAE.

One camp is headed by Rashad al-Alimi, the PLC president, and includes Sultan al-Arada, Abdullah al-Alimi Bawazir, and Othman Hussein Mujalli. The second is led by the head of the STC force, Aidarus al-Zoubaidi, and includes Abdul Rahman al-Mahrami (also known as Abu Zaraa), Tariq Mohammed Saleh, and Faraj Salmin al-Bahsani.

The leaders of both camps issued two different statements regarding the calls made by al-Alimi for the UAE to withdraw from Yemen following the Saudi strike on the ships carrying weapons to the STC. One was in favour of the UAE’s exit from Yemen, and the other was against — showing they are representing the interests of regional players and at the same time confirming that Yemen is a venue for a proxy war.

Within the Yemeni political landscape, the quick developments and successive events are pushing Yemen into a new phase of an internal war among political and military components that make up the legitimate government, with new internal fighting among many armed factions.

It is also taking the focus away from the Houthi rebellion in the north, which controlled Sanaa and the most populous provinces in Yemen.

The main goal for the legitimate Yemeni government and the Saudi-led Arab coalition was to confront the Houthis’ takeover. Now, the country is on the brink of collapse and a new phase of turmoil after more than a decade of armed conflict, which could help the Houthis to expand their influence beyond their current areas of control.

The latest event will weaken the Saudi-led coalition further and cast doubt over its cohesion and ability to achieve its declared joint goals for Yemen.