President Jaafar Nimeiry of Sudan has trouble at home on two fronts.
In the north, in the urban area of Khartoum and Omdurman, he has had to deal with violent protests against the sugar-price increase instituted at the start of the year.
In the south, he is caught up in a dispute over whether the southern autonomous region -- until now a three-province entity -- should be divided into three separate regions. The north has already been divided into five regions, corresponding to the the area's five provinces.
These troubles offer an opening to Libyan leader Muammar Qaddafi, who has long been engaged in a feud with Nimeiry. Recognition of this almost certainly accounts for Nimeiry's policy switch this week on the question of Chad.
President Nimeiry dropped his support of the dissident, vigorously anti-Libyan group inside Chad led by former Chad Defense Minister Hissein Habre. (The Egyptians reportedly have done likewise.) Sudan now has thrown its backing to the Chadian government of President Goukhouni Woddei.
The Nimeiry-Woddei reconciliation took place during a three-day visit to Khartoum by the Chadian President, which ended Jan. 12. The two leaders agreed to set up a committee to ensure that Chadian rebels do not use Sudan as a base.
Until recently, Habre's forces had been doing just that -- with at least tacit approval of Sudan and Egypt. These two countries are believed also to have been conduits for arms supplies to Habre. Sudan's policy switch will be a blow to him. It remains to be seen whether it ends to his rebellion.
Why did Egypt and Sudan support him in the first place rather than the government of President Woddei, who has the blessing of the Organization of African Unity (OAU)?
Because in mid-1980 Woddei called in Libyan troops to help him defeat Habre. Egypt and Sudan viewed Libyan troops on their joint border as a potential threat to the entire Nile Valley, without whose waters neither could survive.
With his troops in place in Chad, Libyan leader Qaddafi tried last summer to cajole Woddei into a merger of their two countries. Woddei resisted.
Earlier that summer the OAU agreed to set up a peacekeeping force, to be sent into Chad if Mr. Woddei asked the Libyans to depart.
Woddei asked the Libyans to leave Oct. 29, and to the surprise of many, Qaddafi promptly complied. The OAU force was not ready to move in to take the Libyans' place, and even now it is not fully deployed. Some analysts believe that Qaddafi's quick pullout was intended to show that Chad could not hold together without a Libyan presence.
Once the Libyans left, the biggest threat to Woddei was Habre, waiting near the Sudan border. With the OAU force so slow in establishing itself and with Habre's men beginning to move toward the Chadian capital, Woddei began hinting at the possibility of bringing Libyans back to keep the peace.
If this happened, none of Chad's neighbors would have felt as discomfited as Nimeiry. Hence his decision to help Mr. Woddei by cutting off Sudanese support for Habre.