The annual East African Community summit is being held amid open hostility not long after Burundi declared Rwanda its enemy.
And not all six heads of state from the member nations – Burundi, Kenya, Rwanda, South Sudan, Tanzania and Uganda – are attending the gathering in the Tanzanian city of Arusha.
Burundi’s Pierre Nkurunziza will be sending his first deputy while South Sudan’s Salva Kiir will be represented by a special envoy.
The summit had been planned for last November but was postponed twice because of boycotts by Burundi, which has accused the regional bloc of turning a blind eye to its poor relations with Rwanda.
Mr Nkurunziza accuses his Rwandan counterpart Paul Kagame of sponsoring a coup attempt against him more than three years ago as well as training armed groups to undermine his country’s security.
Rwanda has always denied Burundi’s accusations.
Meanwhile, Rwanda is complaining about what it calls abductions, torture and arbitrary deportations of some of its citizens who travel to Uganda.
From the official agenda, there is no indication that any of these hostilities will be discussed at the summit.
It is scheduled to review progress towards establishing a common currency and a political federation.
But talks about further integration may not go far without and unless the simmering differences among member states are resolved.