Global Policy Forum

Just visible at the far side of the bridge that links this Liberian town with Sierra Leone, the region's newest militia can be seen patrolling recently conquered territory.

The Nigerian soldiers who guard this sleepy border town are ostensibly peacekeepers in a regional effort to end years of fighting in Liberia. But under cover of nightfall they have reportedly undertaken another mission, arming and training the fighters across the bridge for what is shaping up as this devastated corner of Africa's latest civil war.

The militia members, traditional hunters of the Mende ethnic group known as the Kamajors, say they are fighting to restore Sierra Leone's only democratically elected President, Ahmad Tejan Kabbah, who was overthrown in a military coup in May and who monitors events in his country from exile in nearby Guinea.

Since the coup that forced Mr. Kabbah from Sierra Leone, Nigeria has tried one thing after another to return him to power: a naval blockade; aerial bombardments of military bases, and enforcement of an international isolation so complete that not even foreign mail arrives in the country anymore.

But the military leaders in Sierra Leone's capital, Freetown, shrugged off even pressures like these. So, diplomats say, Nigeria seems to have decided the only course is to back ethnic allies of the deposed President in a military campaign.

In less than 10 years, wave after wave of just this type of militia warfare has taken Liberia and Sierra Leone from the relative comfort of concrete houses and electricity back to straw huts and storm lanterns.

In both countries' capitals, even the downtown streets go unlit at night, so badly have basic utilities like power grids been damaged by the years of war. And through the countryside, the roads that remain passable cut through an endless succession of abandoned, bullet-strafed villages.

The instability that has made this one of Africa's most strife-ridden regions is fed by a complex shadow play of intrigue. Foreign diplomats, Sierra Leoneans and Liberians say that countries both near and far are competing for influence here, and for a rich slice of the region's readily exploitable natural resources.

Over the years, the jumble of players here has included Western powers like the United States and France, as well as Libya, Taiwan, South Africa, ragtag national armies and a multitude of warring militias.

But at the center of the action, almost from the start, has stood the region's one true power, Nigeria. Depending upon who is speaking, that nation is viewed as either the only serious force for stability or a mischievous and determined plunderer of weaker states.

For many experts, the key to the recent history of Sierra Leone and Liberia lies in Nigeria's push to extend its political and economic influence along the West African coast. At virtually every step of the way, these analysts say, France has maneuvered to keep the Nigerian giant in check. The French motivation: eagerness to retain a hold on heavily dependent former colonies.

''It is a West African version of the Great Game,'' said one African diplomat, referring to the secret 19th century British-Russian struggle for mastery of Central Asia. ''They have almost never gone at it directly,'' added the diplomat, who has spent his career watching Nigeria and France compete for influence in the region. ''So it goes unnoticed most of the time. But both countries see the stakes as very high.''

International rivalries have existed in the area since colonial times. But they accelerated sharply in 1989, when Ivory Coast and Burkina Faso, reportedly with French encouragement, helped Charles G. Taylor launch an invasion of Liberia to topple the United States-backed Government of Samuel K. Doe.

With the United States evacuating its citizens from Liberia because of the intensifying violence, Nigeria, whose military Government had strong business ties with Mr. Doe, rallied several other West African nations behind a regional military intervention. The action relied heavily at first on Nigerian jets and gunboats to stop Mr. Taylor's advance.

Mr. Taylor, furious to see his offensive foiled, then began arming a guerrilla movement, the Revolutionary United Front, to punish Sierra Leone for joining the Nigerian drive against him.

Sierra Leone's Government initially relied on Nigerian help for its defense, ceding control of several diamond-rich mining zones to the Nigerians in return. But the rebels steadily gained ground, so Sierra Leone turned to South African mercenaries for help. This left Nigeria doing little more than guarding the airport in Freetown.

For years the situation festered, with the Liberian stalemate producing some of the bloodiest warfare in Africa and the Revolutionary United Front waging a campaign of terror in Sierra Leone.

Nigeria and Mr. Taylor appeared to reach a tenuous reconciliation shortly after his third disastrous attempt to storm the Liberian capital, Monrovia, in April 1996. They continued to work well enough together for Liberia to pull off surprisingly free national elections last July, which Mr. Taylor won in a landslide.

But Mr. Taylor wasted little time in seeking the departure of the Nigerian-led peacekeepers who had frustrated his war efforts. He has also been criticizing Nigerian-led efforts -- a combination of sanctions and force -- to bring down the Sierra Leonean junta.

''It was never clear how the marriage between Nigeria and Taylor could continue to work,'' said one international relief official who has spent most of the decade in Liberia. ''Nigeria clearly wants to dominate this region, starting with Liberia. And Taylor wants as much power for himself in this region as he can get.''

Diplomats in Liberia say Mr. Taylor may be betting that by opposing Nigeria's efforts to restore the elected Government in Sierra Leone he can extend his influence there. The Sierra Leonean military junta has now joined forces with the Revolutionary United Front's rebellion, the one that Mr. Taylor once helped arm.

''A lot of people think that Taylor is in league with the Revolutionary United Front, and perhaps in bed with Libya,'' a Western diplomat said. ''What appears clear is that he is rocking the boat already and wants to make any Sierra Leone peace deal fall through and keep the R.U.F. in power.''

The payoff is potentially great for Mr. Taylor, who continues to enjoy the diplomatic support of France's closest allies in the region. But many say the price of failure could be equally high for Liberia, which is just emerging from its prolonged war.

When Nigerian troops begin leaving Liberia in the thousands, as expected next month, it will be left without a properly trained national army. Mr. Taylor's enemies -- or for that matter Nigeria, in its struggle to consolidate a foothold in Sierra Leone -- could easily use neighboring territory to attack Liberia.

''One doesn't see any easy way out of this cycle of building up external alliances and using them to undermine your neighbor,'' a West African diplomat said. ''Perhaps when all of your fingers have been burned you learn to stop playing with fire.''