Then, in late April, a letter arrived from Bill Clinton. In it, the president firmly told Mobutu that the time had come, at last, for him to go. The message marked the formal conclusion to America’s relationship with a dictator it had supported for more than three decades. For central Africa, the letter signaled something more significant: that the United States intends, once and for all, to establish itself as the dominant power in the region. After Mobutu’s departure, sources in Africa have told NEWSWEEK, the new transitional government will turn away from France and Belgium, two traditional patrons, and tie itself more firmly to another, the United States. Subject to a referendum, the nation’s name will be changed, possibly to Congo-Zaire, and its capital will be moved to Kananga, at the head of a rail line recently rebuilt by, and connected to, South Africa, Washington’s key ally in the region. English will become one of two official languages, along with French. The country will be given a constitution and a police force based on U.S. models. “We have the American system on the table,” says Beya Mulumba, the general secretary of the rebel alliance. “We’re not going to waste time trying to invent our own system.”

Washington insists it does not intend to create an American Congo, possibly because it does not want to be blamed for the excesses of the new regime, including the slaughter of refugees in eastern Zaire. “In no way did we throw our support behind Mr. Kabila,” says State Department spokesman Nicholas Burns. No matter. Kabila isn’t likely to be Mobutu’s permanent successor. He has promised to step down as leader after a yearlong transition to elections, possibly to take the post of defense minister. If a free and fair vote can be held, the leader of the new Congo could be former prime minister Etienne Tshisekedi, the country’s most popular politician and long a U.S. favorite.

The job of negotiating Zaire’s immediate future has fallen to Bill Richardson, President Clinton’s chief delegate at the United Nations and now his personal representative in Zaire. Last week Richardson helped organize a summit meeting between Mobutu and Kabila, whose forces control three quarters of the country. But the two rivals took turns refusing to board a South African ship where the talks were to be held. Not even the compelling presence of South African President Nelson Mandela could get the summit started on time.

America’s current involvement with Kabila has its ironic side. In the 1960s and ’70s, it was mainly the United States, France and Belgium that put Mobutu in power and helped to keep him there as a bulwark against their cold-war rivals. He was a “useful tyrant,” and as the West protected him from enemies at home and abroad, it tolerated his corruption and autocracy. Mobutu earned his keep. In his last great service to Washington, he allowed his territory to be used for the CIA’s paramilitary operations in support of anti-Marxist rebel Jonas Savimbi in Angola. But by the time that operation was wrapped up in the 1980s, the Zairean dictator had outlived his usefulness, and the CIA cut him off.

In the years since the end of the cold war, Washington seems to have muddled through effectively in Africa (apart from its Somali debacle), despite frequent accusations that it lacks a coherent Africa policy. Post-apartheid South Africa has become a far more useful and reliable U.S. friend than the country ever was under white rule. Former adversaries in Angola have been converted into friends.

Now, as Clinton plans his first official visit to Africa within the next year, politicians and other officials across central Africa say the Americans are making their move in Zaire by helping Kabila’s war effort. In Burundi, a top intelligence official claims that U.S. military cargo planes rushed equipment to Kabila as he began his offensive last November, landing under cover of darkness at Entebbe in Uganda and Kigali, the Rwandan capital. One of Mobutu’s former security chiefs asserts that U.S. weapons were diverted to Kabila’s forces from Somalia and that U.S. military advisers scouted battlefields and march routes for the rebels, on the ground and from the air. There also are rumors about U.S. military advisers working at the Kamina air base in Zaire’s Shaba province.

Washington admits to having a small number of military observers and logistical experts in Zaire, Rwanda and Congo-Brazzaville, across the river from Kinshasa. In addition, about 1,400 U.S. troops are on hand in Brazzaville or with a U.S. fleet offshore, in case it becomes necessary to rescue the fewer than 400 Americans who still live in Zaire. Washington insists it has no other military involvement, but among Africans, it has become an article of faith that the United States is intervening. “The Americans saw a hole and pushed through it,” says one African politician.

What does America stand to gain? The new Zaire offers a bonanza to U.S. investors, who already are flocking into rebel-held territory. And a friendly new regime in Zaire can help Washington ensure U.S. security against terrorism and other threats from rogue states such as Sudan or Libya.

For the French, the sight of the Americans moving in is plainly excruciating. That the Americans are taking over with so little effort, barely seeming to pay attention at times, adds insult to the injury. “Africa is fundamental for France, whereas it is not for the U.S.,” says French political scientist Zaki Laidi, author of a book on geopolitical rivalries in Africa.

Of course, if Zaire splinters, no one will have an advantage. And it’s not clear that Kabila has complete control over his own final offensive. In the south, the rebel attack is spearheaded by troops, armor, aircraft and artillery provided by Angola, which has a long history of grievances against Mobutu. The northern pincer of the rebel drive is stiffened by support from Uganda and Rwanda, united by ties of blood and politics to Kabila’s fighters, many of whom come from the Tutsi tribe of central Africa.

The rebels’ quick conquest of territory shows how deeply foreign troops are involved in the offensive. Despite Mobutu’s weakness, it never made much sense that a ragtag army composed entirely of Zairean rebels from the Tutsi tribe could march all alone across a huge country. Now the danger is that the disparate forces within the alliance will turn on each other, ultimately breaking up Zaire. Already, there are reports of battles between Tutsi troops and non-Tutsi Zaireans backed by Angola. Kabila himself, who belongs to the Luba tribe, seems to fear that the Tutsis are after his head. He has surrounded himself with Angolan bodyguards and an Angolan pilot, and in recent weeks, he has spent most of his time in the southern city of Lubumbashi, far from the Tutsis.

The rebel military campaign is being conducted amid an almost total news blackout. Not a single independent journalist has been allowed near what little fighting has occurred. “Things that aren’t so Catholic happen at the front. We don’t permit [coverage],” says a top alliance official. Even when Kinshasa falls, he adds, there will be 48 hours of cleanup before reporters are allowed on the scene.

The rebels could not cover up the tragic plight of the Hutus in eastern Zaire. As many as 100,000 refugees from neighboring Rwanda hid in the forests, terrorized by Kabila’s Tutsi forces. The atrocities in the forest and the battle for Kinshasa might have been avoided if Mobutu had given up power earlier. Months ago, Kabila offered his rival a chance to retire to his white marble palace in the remote northern jungle at Gbadolite. But in 32 years of magisterial rule, Mobutu has come to think of himself as a monarch. He had groomed his son, Mobutu Nyiwa, as his successor, but the young man died of AIDS, sources say. Now Mobutu relies on the advice of his second wife, Bobi Ladawa, who adamantly opposes any concessions.

African strongmen can be difficult clients. As word spread of the atrocities against refugees, Richardson urged Kabila to punish those responsible. The rebel leader said he was doing all he could. U.S. diplomats quoted him as saying: “I want to be helpful, but I can’t control all of my people.” The United States has a similar problem with Kabila and his assorted bedfellows. Now that American is the great power in central Africa, whatever the rebels do, or fail to do, will reflect on Washington.