U.N. and African mediators announced on Tuesday that South Sudan’s president Salva Kiir and rebel leader Riek Machar have agreed to a ceasefire. A political agreement signaling a common desire to curb South Sudan’s internal turmoil made by these two political adversaries and erstwhile guerrilla allies is a major step toward preventing a much larger East African regional war.

However, stopping and then limiting the damage of the Dinka versus Nuer tribal war spawned by the murky late evening events of Dec. 15 in South Sudan’s capital, Juba, may be much more difficult. Kiir is Dinka. Machar is Nuer. In July 2013, Kiir fired Machar as vice-president, after Machar accused Kiir of undermining democracy and favoring his Dinka cronies with government largesse.

Kiir supporters accuse pro-Machar rebel soldiers in the Sudan Peoples Liberation Army (South Sudan’s military) of attempting a coup on Dec. 15. Machar supporters accuse Kiir’s Dinka-dominated presidential guard of deliberately fomenting a dispute with Nuer soldiers and then opening fire in order to establish a political pretext for purging Machar’s political allies. Whatever sparked the battle in Juba, fresh blood has spilled between the tribes. Mutual accusations of mass murder and ethnic cleansing have followed the bloodbath. Fighting has erupted in five of South Sudan’s ten states. Two SPLA generals (both Nuers) commanding two major state divisions defected to Machar. Other tribes and clans have chosen sides.

But let’s return to the tentative ceasefire. The U.N., the African Union and numerous other countries (including China and the U.S.) back the deal. Moreover, several East African nations, including three of South Sudan’s neighbors, Ethiopia, Kenya and Uganda, have made a commitment to support South Sudan’s national integrity.

That commitment sends a tough message to Sudan’s president, indicted war criminal and South Sudan’s nemesis, Omar al-Bashir. Bashir openly covets South Sudan’s oil fields. His Islamist regime in Khartoum lost billions in oil revenue when South Sudan became independent in 2011. With South Sudan rent by tribal conflict, Bashir might seek to regain control of South Sudan and end its existence as an independent state.

Kenya and Uganda both deploy highly capable military units. Ethiopia has become East Africa’s most potent military power. Its air force negates Sudan’s air advantage over South Sudan. Moreover, Ethiopia already has troops on the ground. An Ethiopian peacekeeping brigade, under U.N. mandate, patrols the disputed oil-producing Abyei region between Sudan and South Sudan. Sudan cannot completely ignore the U.N. forces assigned to the U.N. Mission in South Sudan. The U.N. has reinforced UNMISS. China has a UNMISS troop contingent, and Bashir has relied on China as a source of weapons. All in all, South Sudan’s regional and international support makes an overt military move by Khartoum unlikely.

However, Khartoum would delight in thoroughly destabilizing South Sudan by pitting ethnic faction against ethnic faction. In fact, South Sudan regularly accuses Sudan of doing just that; in turn, Khartoum accuses Juba of supporting rebel groups within Sudan.

Can South Sudan be “put back together again” or is it a lost cause? The answer is, yes it can. An immediate example of the restoration and reconciliation process may have occurred late last week when wire services reported that on Dec. 29, after days of discussion, Nuer tribal elders in Jonglei state convinced several thousand young fighters in a Nuer “White Army” militia to go home. The warriors were en route to fight pro-Kiir forces in the state capital, Bor. Though the entire force did not disband; the elders managed to cool some very hot heads.

I’m speculating, but the reports suggest the elder practiced discrete peacemaking. In the mid-1990s Catholic and Anglican Church mediators (most operating out of Kenya) began reconciliation discussions between Nuer and Dinka tribes in South Sudan. The discussions didn’t directly address political disputes, but focused on reconciling personal disputes, sharing common stories of suffering and establishing common interests between tribes and clans living in the same immediate area. Tribal elders played key roles. Tribe members had to ask if they really wanted to kill their neighbors or would they prefer shared peace?

In 1991, during the long southern rebellion against Khartoum, Machar split with the SPLA and allied with Sudan. His reason? Dinkas unfairly dominated the SPLA. Sudan’s government, led by Bashir, used Machar’s defection as an opportunity to roll back SPLA gains in the south. But then the war stalemated and everyone suffered. Machar and his Nuer did not rejoin the South Sudan rebel movement until 2002. Why? Bashir’s Islamists tried to escalate Nuer-Dinka disputes with the goal of damaging both tribes. The Nuer-Dinka discrete peacemaking efforts made reconciliation possible.

South Sudan must make that effort once again.

Austin Bay is a syndicated columnist.

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