South Sudan's vow to stop talking with counterparts in Sudan might score political points for both sides, but economically and strategically the countries desperately need each other.
Both Sudans suffer when talks falter
To mark his country's first anniversary on July 9, South Sudan's President Salva Kiir called on his countrymen to be patient. In turn, he promised to pursue peace and economic normalisation with their former compatriots in the north.
"Although the Republic of Sudan has declared South Sudan as their number one enemy," Mr Kirr said, "we still remain committed to peace, good relations and free trade with Sudan."
Fine words, and ones that are being tested. On Saturday, southern leaders called off face-to-face peace talks, accusing Khartoum of bombing a border village while residents slept. Khartoum denied the accusations.
Hostilities might win political points for Mr Kiir at home - as well as for Sudan President Omar Al Bashir, who in recent weeks has faced protests in Khartoum - but economically both countries desperately need each other.
Even as South Sudan's flag was being raised last year, a laundry list of troubles was obvious to anyone who cared to look. There are centuries-old tribal and religious rifts on both sides; responding to every provocation will only deepen these enmities.
The details of border skirmishes will usually be unclear to outsiders, and often the result of localised tribal and territorial disputes. While Khartoum has rejected the suggestion that it fired across the border at the weekend, both sides have been guilty of supporting cross-border violence in recent months. In April, a build-up of forces around the oil-producing town of Heglig almost pushed the two nations into open conflict.
Continuing talks in the Ethiopian capital had offered the best opportunity to resolve these and other issues.
Mr Kiir is correct: his country cannot progress economically without improved relations with Khartoum. South Sudan's budget is in a shambles as oil revenues have been constricted, along with the flow of oil to refineries in the north. The promise of Juba's celebrations last year could turn into a curse for an impoverished people.
That is equally true for Mr Al Bashir. The protests in Khartoum, now somewhat diminished, showed that business as usual was no longer possible; South Sudan's independence, and the dissipation of national oil revenues, will force Sudan to adapt as well.
Last week, Mr Al Bashir and Mr Kiir posed together for a photo op, in a brief flash of detente. It is time for both to stop posing and start talking.