Yemen's five-year civil war is taking on a new dimension, this time at the hands of a group once allied with President Abd Rabba Mansour Hadi.
Over the weekend, Yemeni separatists took over most of the southern part of the city of Aden, the de facto capital of the country's internationally recognised government.
Four days of fighting – which killed 40 and wounded over 250 – took place between the Security Belt, a group aligned with the Southern Transitional Council (STC) backed by the United Arab Emirates (UAE), and the Hadi government.
This is the same government that was driven from the capital Sanaa after Houthi rebels took over.
Since then, the Saudi Arabia-led coalition, in conjunction with the United Arab Emirates, has engaged in arming and sheltering Hadi and his government to take back control of the country.
But this latest takeover by the separatists is seen as a major blow to the country's internationally recognised government, as it no longer has as stronghold in either Sanaa or Aden.
A new dimension in the five-year civil war
“Divisions within the South are deepening, and we see the further disintegration of Hadi's regime and the coalition attempting to restore him to power,” says Sheila Carapico, a professor of political science specialising in the Middle East and Yemen.
“There seems to be chaos in Aden right now, but many are celebrating the collapse of the regime in the city.”
Following its victory, the head of the STC, Aidarous al-Zubaidi, said on Sunday that the violence was provoked by forces loyal to Hadi following attacks that began on 1 August during a military parade in Aden.
Al-Zubaidi added this violence presented the separatists with a choice.
“As the scene became clear, we had only two options: either self-defense, or surrender and accepting the liquidation of our just cause before the liquidation of our souls, so then we made our decision that was guaranteed to us by heavenly and international laws to defend ourselves.”
But he did stress that the STC was willing “to stand fully with the Arab Coalition to fight Iranian expansion in the region under the leadership of the Kingdom of Saudi Arabia”.
In response, Hadi's government accused the STC and the UAE of staging a “coup” against it.
Tensions within the coalition
What was once a united and deadly alliance against the Houthis appears to be waning, especially the links between the UAE and Saudi Arabia.
“There is a rift between the Kingdom of Saudi Arabia and the UAE, and within the Gulf Cooperation Council (that used to be united on its Yemen policy). It is difficult now to discern who is in the erstwhile Saudi-led coalition,” adds Carapico.
What was supposed to be a united front in Aden against the Houthis has now fallen apart and exposed itself to be two forces: Hadi's forces supported by the Saudis and separatists supported by the Emirates.
And there's never been a big secret that those in the South have sought independence, especially since the official formation of the STC in May 2017. “It has been developing for a while and now seemingly reached a tipping point,” notes the professor.
Yemen has always been different than its other regional neighbours, but in particular is the division between north and south.
Under the Ottomans, the country split into two when the south sought its independence. Soon after, however, it was taken over by the British, and it wasn't until the push for pan-Arabism hit the region in the 1960s that the Yemenis were able to kick out the British in 1967.
At that point, southern Yemen was the “only Marxist country in the entire Arabian peninsula”, says Adam Baron, a visiting fellow at the European Council on Foreign Relations and International Security Programme fellow at the journal New America.
“The southern dimension is often ignored by almost all the interventions that the international community make to try and resolve the conflict,” says Nadwa al-Dawsari, Yemen country director with the Center for Civilians and Conflict.
The two nations remained separate until unifying in the 1990s, but tensions grew between the two regions, leading to the 1994 civil war.
Afterwards, the southerners felt marginalised and left out of major key government decisions, says al-Dawsari.
And then again, as efforts were made to restabilise relations, tensions increased, culminating in the 2011 uprising and finally in the 2014 war after the Houthis took over Sanaa.
Al-Zubaidi did confirm the council's willingness to commit to a ceasefire called by Saudi Arabia, adding he would partake in Saudi-brokered peace talks.
But with a new element introduced to the ongoing conflict that already has proxy wars going on between Iran, Saudi Arabia and the UAE, it's difficult to see how a lasting peace deal can be agreed on that would satisfy the north-south divide, along with that between the Houthis and the Hadi government.