Nimble diplomacy by French President Mitterrand has blocked - for the moment at least - an apparent move by Libyan leader Muammar Qaddafi to tighten his hold on Chad.
Some 10,000 Libyan troops have been in Chad since the end of last year. They were invited in by Chad President Goukhouni Woddei to help him win a civil war against his former defense minister, Hissein Habre. But the Libyans are not popular in Chad, and last week Mr. Woddei asked them to withdraw.
French President Mitterrand saw this coming and has been quietly moving to strengthen Mr. Woddei's hand to enable him to stand up to the Libyan leader. (Qaddafi has been putting pressure on Woddei to agree to a formal political union with Libya.) Initially, the French promised economic aid to Mr. Woddei. But last week, French Foreign Minister Claude Cheysson confirmed that limited military aid was being sent, too.
France has always had a special interest in Chad, one of its former colonies. Until last year, when the Libyans moved in, it had continued, in effect, as Chad's patron.
Parallel with his dispatch of economic and military aid to Chad, Mr. Mitterrand sought to expedite movement to Chad of a peace-keeping force by the Organization of African Unity (OAU). An OAU spokesman in N'Djamena, capital of Chad, said Nov. 1 he expected the peace-keeping force to be deployed by the end of the year.
Mr. Mitterrand's maneuvers were helped by having President Reagan, US Secretary of State Alexander M. Haig Jr., and Nigerian President Shehu Shagari on hand for consultation at the North-South meeting in Cancun, Mexico. Mr. Mitterrand's moves are welcomed by the State Department. Nigeria's interest and cooperation are important because of the country's size and influence.
Nigeria has agreed to provide 8,000 men for the OAU force, Senegal has agreed to send 2,000, and the Ivory Coast 1,500, according to the London weekly the Economist. The Paris newspaper Le Monde says the French Air Force is being used to assemble them. Egypt and Kenya may also send troops.
The French have bases in the Central African Republic, which has a common border with Chad. Before any current movements, an estimated 1,700 French troops were stationed there.
The Economist said that Mr. Mitterrand had promised Senegal that if the Libyans resist the OAU force in Chad, the French Foreign Legion will intervene.
Colonel Qaddafi's immediate reaction to all this has been to deny to Mr. Mitterrand (through the French ambassador in Tripoli) any Libyan intent to force a union between Chad and Libya. That still leaves open the question of whether the Libyan leader will comply with the Chadian request that Libyan troops be withdrawn.
If he refuses, he will be:
* Implicitly flouting the OAU, of which he is due to become chairman next year.
* Risking confrontation with France, which is quietly building up its military strength in the area.
* Prolonging a Libyan involvement in a basically inhospitable land where military service is increasingly dreaded by young Libyans who are subject to draft for undefinite periods.
If Qaddafi decides he cannot accept the loss of face that withdrawal from Chad might bring, he still has a hand in its politics through a man who may be more willing to do his bidding than is Woddei. That man is Chad's nominal foreign minister, Ahmat Acyl.
There have been some outside developments in recent days that might have been coordinated to help Qaddafi save face:
The United States withdrew the two AWACS aircraft sent to Egypt to monitor Chad's border with Egypt and Sudan. Public rhetoric denouncing Qaddafi has been muted in Sudan - even perhaps even in the US. Reports from the Sudan-Chad border suggest a sudden diminution of incidents there. Those incidents, encouraged sometimes by Sudan and Egypt, were another reason for Colonel Qaddafi to keep his troops in Chad.