Yet another part of Africa may have been opened up for Soviet exploitation by Libyan leader Muammar Qaddafi's latest success -- this time across his southern border into Chad.
There, Libyan arms and men have given victory to head of state Goukhouni Woddei, thus making the latter beholden to Colonel Qaddafi.
This has left France -- once Chad's protector and patron -- outmaneuvered, if not humiliated, the mainly French -- speaking sub-Saharan African states scared, and Chad's two African neighbors of consequence, Nigeria and Sudan, infuriated and alarmed.
For the Western Alliance, and many outside it, the disturbing thing about this Libyan beachhead across the Sahara into Africa proper is the opportunity it offers the Soviet Union.
Colonel Qaddafi is a revolutionary Muslim fundamentalist and no communist. But he has a paradoxical relationship with the Soviet Union, which apparently is only too willing to sell him arms in return for some of the hard currency thinly populated Libya earns from its coveted low-sulfur oil.
He already has stockpiled in Libya more Soviet arms than his own armed forces can use -- several thousand tanks, combat planes, artillery, and other military hardware. Soviet personnel reportedly are guarding them near Tobruk, Libya.
Perhaps offsetting somewhat the major plus represented by Colonel Qaddafi's success in Chad is a simultaneous minus -- his being left empty-handed after a visit to Tripolo Dec. 15 to 17 by Syrian President HAfez Assad, which the Libyan leader had hoped would put the finishing touches to the proposed Libyan-Syrian merger.
Colonel Qaddafi, like an overzealous suitor, first pressed this union Sept. 1 of this year on President Assad. Most observers have been skeptical from the outset about the consummation of this merger, not least because Libya and Syria are separated by 500 or 600 miles of the Mediterranean.
Chad is a different question. There, Colonel Qaddafi is interested in real estate rather than something as ephemeral as political union in the Arab world has hitherto turned out to be. Chad has a common frontier with Libya. In Libyan hands, or under Libyan control, it is a bridgehead across the Sahara from Muslim North Africa into black Africa proper --sub-Saharan Africa known as the Sahel.
Colonel Qaddafi started nibbling at Chad in 1973 when he occupied the 27,000 -square-mile Aozou Strip on the Chad side of the border of the two countries. The strip is said to contain iron and low-grade uranium ore.
The Sahel has two distinctive features, other than geographical proximity, which make it attractive to Colonel Qaddafi as an area to exploit to his advantage. One is that most countries in the Sahel belt are wholly or partly Muslim and therefore susceptible to the appeal of the Libyan leader's Islamic fundamentalism.
The other is that the French-speaking countries in the belt, once part of the French empire, remain to a great extent dependent on France, both for their security and economic well-being. In return, France retains an influential foothold in Africa. But, as Colonel Qaddafi (and others) see it, this situation gives an opening for infiltration of his brand of anti-Western imperialism.
From the outset, Chad was vulnerable to such pressures more than any other of the Sahel lands. The division between its scattered northern Muslim population and the more concentrated (and blacker) non-Muslim peoples in the south was more stark than in most other countries immediately south of the Sahara.
When the French granted Chad in independence in 1960, they handed power over to the black, southern non-Muslim political elite, fragile though it was. The French Army continued to control the Muslim north until 1965, and there was a residual French military presence in the Chad capital, N'djamena (once the Foreign Legion outpost, Fort Lamy), until May of this year.
After the witdrawal of the French Army from the north in 1965, open trouble between Muslim notherners and the non-Muslim southern-run government in N'djamena began. When Colonel Qaddafi seized power in Libya in 1969, Libyan aid to the northern rebel movement was stepped up.
After the assassination of President Tombalbaye in 1975, the situation began to deteriorate further, with northerners gradually gaining the upper hand. But by March of this year, the northerners were fighting each other under the rival banners of President Woddei and his Minister of Defense, Hissein Habre.
To boost his position in the face of the stalemate that soon developed in the civil war, President Woddei signed a defense agreement with Libya in June. Late in November, a cease-fire agreement was drafted under the auspices of the OAU. Mr. Habre refused to sign it -- but President Woddei did. With the help of about 50 Soviet-built Libyan tanks, Libyan aircraft, and up to 2,000 Libyan military men, Mr. Woddei launched an offensive on Mr. Habrehs redoubt in N'djamena on Dec. 6.
The next day, Mr. Habre's stronghold was overrun. He himself fled overnight Dec. 14-15 to neighboring Cameroon, where on Dec. 16, in the wake of defeat, he finally signed the cease-fire agreement.