A triangular great-power struggle could be shaping up over the continued presence of 12,000 Libyan troups in the sub-Saharan African state of Chad. The three great powers involved are the United States, the Soviet Union, and France.
Given the newly developing association between the Soviet Union and Libyan leader Muammar Qaddafi, it can be assumed that Moscow is on the side of keeping the Libyan forces in Chad. Colonel Qaddafi said publicly at the beginning of the month that they had to stay because Chad was "a strategic ramp" into Libya from the outside.
Both the US and France want the Libyan troops out, but there is a risk that the two Western powers will find themselves at odds about the best way to secure the troops' withdrawal.
France, under its new Socialist President, Francois Mitterrand, is exploring the path of diplomacy and is offering Chad President Goukouni Woddei -- who initially invited the Libyans -- limited French economic help to lessen his dependence on Colonel Qaddafi.
For the US, with the Reagan administration in its present tough anti-Qaddafi and anti-Soviet mood, the temptation is to choose instead confrontation and support for open, armed resistance to any anti-Libyan and anti-Goukouni forces in Chad.
The Libyan troops in Chad are more than a local threat: From the outset they have had the potential of becoming a pawn in the superpower struggle between the US and the USSR. Colonel Qaddafi has been drawing ever closer to Moscow, and his troops could therefore become Soviet proxies in Chad or even farther afield in Africa.
To the east the troops threaten the pro-Western governments in Egypt and Sudan.
To the south and west, backed by Colonel Qaddafi's oil wells and proselytizing revolutionary brand of Islam, they threaten to destabilize all the sub-Saharan states with Muslim populations or minorities -- from Nigeria, the populous giant of black Africa, to the sparsely peopled, impoverished smaller French-speaking states still largely dependent on France for their survival.
Against this background should be seen:
* The impending visit to Washington Sept. 25-29 of the French Cabinet minister most deeply involved in applying French policy in Chad, Jean-Pierre Cot.