Dangerous trouble has started on the border between Sudan and South Sudan, and it could very easily become a much wider conflict unless the leaders of both north and south act with great restraint. After the January referendum voted South Sudan into existence, the north accepted the result of the people's vote.

But there was always a horrible potential for trouble, particularly in the disputed region of Abyei. Now President Omar Al Bashir has said that the northern army has occupied Abyei, saying "Abyei is northern Sudanese land." The United Nations has reported that southern troops attacked a UN convoy escorting northern soldiers as they pulled out of Abyei on May 19. The hopeful calm of the past few months is not likely to last. Both sides want the oil revenue, and neither seems ready to share it.

This is where some outside parties may be able to mediate. The GCC is far too busy with Yemen and other issues, and the closest Arab states are Libya and Egypt, both of which are unable to help much at this stage. But they, and the GCC, should lend their support to an African state which could mediate.