The personal animosity and competition between the sons of the late Sheikh Abdullah bin Hussein al-Ahmar (Sadiq and his nine brothers) and the sons and nephews of Saleh have been a consistent obstacle to negotiations over a peaceful transfer of power. Now, this animus threatens to drag the country toward a full-scale civil war. While fighting has centred primarily on these two groups, it could easily escalate, drawing in other tribal factions, Yemeni regional actors as well as the first armoured division controlled by the powerful military commander, Ali Mohsen al-Ahmar.

Already, the conflict has widened beyond the personal feud. During the course of a tribal mediation attempt, Saleh’s security forces fired on Sadiq’s home, killing several prominent sheikhs and injuring dozens of other individuals, including one of the president’s closest allies and trusted negotiators, Ghalib Ghamish – head of Political Security, Yemen’s intelligence service. Armed confrontation since 23 May has cost over 100 lives. The civilian population in the capital of Sanaa is at great risk, as the two sides battle each other in densely populated urban areas. Hundreds are fleeing, fearing a tribal invasion from the countryside.

Urban youth and civil society activists, who initiated the protest movement, stand to lose the most from this turn of events. Their voices will almost certainly be sidelined in the power competition between entrenched and heavily armed factions of the tribal elites. Should the conflict escalate and drag on, the spectre of state fragmentation will be raised, as groups in south Yemen may view a prolonged confrontation in the north as an opportunity to form a separate state of their own.

If the immediate priority is a ceasefire, the next step must be to de-escalate tensions. This can only be done through a managed political transition under which President Saleh would accept a swift transfer of power to an inclusive, civilian caretaker government. The Gulf Cooperation Council (GCC) initiative – which proposes a “30-60 Transition Plan” whereby the president would transfer power to his vice president after one month in exchange for immunity for prosecution, and a coalition government, headed by the opposition parties, would hold presidential elections two months after the president’s resignation – may still serve as a basis for such a transition.

However, it should be quickly amended to reflect new political developments and the need for a more inclusive transitional process. In particular, it may be necessary to:

• shorten the 30-day timeline for President Saleh to transfer authority to his vice president;

• describe with greater specificity the tasks each party to the agreement will be required to implement and the timeline by which they are to be completed, as well as oversight mechanisms to ensure this happens;

• broaden participation in the transitional government to include youth and civil society representatives, the Huthi-led rebels in Saada, members of the former leadership of South Yemen currently living in exile as well as members of the southern movement (Hiraak) willing to pursue reform within a unified Yemen; and

• expand involvement by the Friends of Yemen group (which includes the GCC, members of the G8, and representatives of the UN, the European Union, Arab League, IMF and World Bank), including by conditioning economic aid and other assistance on successful implementation of the transition initiative.

Increased international engagement is necessary to arrest Yemen’s descent toward armed conflict. But, given the deeply personal and tribal nature of the feud between the Salehs and al-Ahmars, it cannot be addressed effectively by international mediation or initiatives alone. Because Yemen’s political trajectory will be primarily determined by domestic political forces and shifting alliances, the responsibility now lies squarely on domestic mediators to first avoid a dangerous escalation in violence through a ceasefire agreement and then to contain the toxic conflict between the young generation of Salehs and al-Ahmars.

Ideally agreement would be reached to exclude or limit both groups’ involvement in the transitional period. This would provide new incentives for Saleh and his family to relinquish power, as they fear the immediate dominance of the al-Ahmar family in the aftermath of the president’s resignation. It also would give Yemenis additional political space to forge new alliances outside of these two dominant power centres. Left unaddressed, this interfamily competition can only inflame further violence and continue to undermine aspirations for genuine and meaningful reform.