The aftermath of the murder of Tom Mboya has mocked what he stood for. Mboya, who seemed to represent all that was modern in Africa to the rest of the world, always shunned the appeals to tribal allegiance that have crumbled political stability elsewhere in Africa. His constituents were mainly the urban workers groping for a modern way of life. Yet his assassination on the first Saturday in July unleashed intense tribal hatreds. Kenya faces a long and dangerous period of instability unless the government can somehow placate his grieving Luo people.

Mboya was shot and killed in downtown Nairobi on a street crowded with shoppers trying to make their last purchases before stores closed for the weekend. Two weeks later, police charged a young African with the murder. They released no details about him but his name, but that was enough to confirm all the suspicions that had been excited by tribal passions. The name, Nahashon Isaac Njenga Njoroge, identifies the accused as a member of the dominant Kikuyu tribe, the people of President Jomo Kenyatta. Without a shred of evidence, most Luos, whether educated townspeople or illiterate peasants, had decided from the beginning that the killer must be Kikuyu. Now they had proof.

The Kikuyus are the largest tribe in Kenya — perhaps 2 million of the country’s 10 million people. Aggressive, better educated than other tribes, solidly behind the government, the Kikuyus have dominated independent Kenya, holding the presidency, several key ministries, and a disproportionate share of top civil service positions. The Luos, the second largest tribe with 1.3 million, have never gained their share of the fruits of independence. Their political divisions have hurt them. A large number accepted the leadership of Mboya and supported the government. He was a founder and the general secretary of the ruling party, the Kenya African National Union (KANU), and the minister of economic planning and development in Kenyatta’s cabinet. But many Luos, perhaps the majority, followed the tribal call of Oginga Odinga, a Luo chief who was a long-time enemy of Tom Mboya and the leader of the opposition Kenya People’s Union (KPU).

As soon as news of the assassination reached them, the division was healed. Most Luos blamed KANU, Kenyatta and the Kikuyus, and reasoned that if Kenyatta’s KANU did Mboya in, they all must support the other party, Odingas KPU. “Tom, why did you join with them?” they shouted in Luo as the funeral procession brought Mboya’s body back to Luo land. “When things get worse,” a mourner chanted at the graveside, “there is only one man who can save us. That is Jaramogi [Odinga’s Luo title]. Where is he? I am looking for him in the crowd.” Ironically, Mboya’s old political enemy, Odinga, became the hero of the Luos mourning for Mboya. Tribal hatred had melted political alignments.

On July 8, jeering, mostly Luo crowds in Nairobi hurled stones and shoes at the long Mercedes of Kenyatta as it took him to a requiem mass for Mboya in the Roman Catholic cathedral. The crowds chanted the Swahili word, dume, and stabbed their right thumbs upward in the air. Both dume — the Swahili word for bull — and the upward thumb thrust are symbols of Odinga’s KPU. The jeering and the stone throwing frightened and enraged the police, who began swinging their axe handles at the crowd and firing tear gas. The outburst set off three hours of rioting, which damaged scores of cars and killed two persons, including a young German, stoned as he drove home from work.

It was a sad and singular day for Kenyatta, the mzee or old man of Kenya politics. Never before had Africans jeered him publicly. The old African nationalist, now almost 80, had long been looked on as the father of the young country. But blinded by hatred and anguish, many Luos now saw him more as the leader of his Kikuyus than of his country. Tribal feelings were even more raw in the Luo areas of western Kenya. When word of the killing spread, Luos hunted for Kikuyus in their midst. One was beaten to death, and the government had to evacuate all the Kikuyus from the rural areas of the Luo people. The anti-Kikuyu feeling was intense at the burial of Mboya in his traditional family homestead on Rusinga Island in Lake Victoria. “War, War,” Luos shouted. “War with the Kikuyus.” A self-proclaimed witch doctor chanted, “May the wombs of all Kikuyu women dry up.” Another mourner shouted, “Where is Jomo Kenyatta? If he were here, even if he were guarded by 100,000 soldiers, I would kill him.” Every non-Luo member of the cabinet stayed away from Rusinga Island.

Mboya, who was 38 when he died, had made many enemies during a political career that began when he became a labor union leader in 1953. Other African politicians resented his popularity abroad. Jealous and annoyed, they felt the rest of the world saw him as the magazine cover boy of Africa. In addition, Mboya had an arrogant manner that lost him political friends. He was cold, tough and superior, and that frightened or angered many of his colleagues.

Odinga, resentful that this young Luo had not stepped aside for him, always tried to thwart the ambitions of Mboya. Before independence, Odinga helped revive the popularity of Kenyatta to frustrate any hopes Mboya might have had to take control of the country. The young Kikuyu politicians also sided very quickly against Mboya, even though they all belonged to the same party. They were jealous of him, for he had won renown in the Mau Mau years when the British had banned all political activity by the Kikuyus. They believed that the place held by Mboya rightly belonged to them.

As long ago as 1962, Mboya told me: “There is no doubt that the young Kikuyu intellectuals are against me. I am aware of this. It is nothing new. The problem is that there is no second man to Kenyatta whom they see as the leader of the Kikuyus. I represent a threat to them.”

But at the time of his death, Mboya’s chance of succeeding Kenyatta as President seemed slight. His path was blocked by an alliance between these same young Kikuyu politicians and Vice President Daniel arap Moi, a member of the small Kalenjin tribe. Few outsiders, however, were ready to count Mboya out completely. He had a way of outsmarting hostile alliances.

Since the assassination, Nairobi has been inflamed with rumors about the identity of the plotters, since few believe that Njoroge acted on his own. The rumor mongers have little evidence to back up their accusations, but some facts should emerge when the trial of Njoroge begins. Whatever its outcome, however, Kenyatta’s government must deal with the tribal hatreds unleashed by the killing. As the Rt. Rev. Maurice Otunga, an Abaluya tribesman who is the Catholic bishop in the Luo area, put it, “Mzee now has to show that his government is not a Kikuyu government.” But the government’s response to the threat of tribal conflict was at first hesitant and vague. Eleven days passed before President Kenyatta made a radio appeal to the nation for “unity, love and peace.” Meanwhile, Vice President Moi had hinted, in an unclear and stumbling way, that the government would try to prove that Communists were behind the murder. Mboya’s death then could be laid to outside Reds rather than inside Kikuyus. Luos, however, would have had difficulty believing the theory.

Later, the government began to move more decisively. On July 24, Kenyatta appointed Joseph Odero-Jowi, a Luo and close friend of Mboya, to succeed Mboya as minister of economic planning and development. A second Luo was named to take Odero-Jowi’s place as minister representing Kenya on the East African Community. Kenyatta picked still a third Luo as assistant minister for foreign affairs. To soothe Luo feelings, however, the government must also start appointing more Luos to posts in the civil service.

Tribal conflict is not the only legacy of Mboya’s assassination. His murder destroyed the touchstone of Kenya’s politics. For years, its politicians had one main issue on which to align themselves: they either sided with Mboya or ganged up against him. With Mboya dead, a new politics will have to develop; the murder has crumpled all the old assumptions.

Kenya also will feel the loss of Mboya’s technical and organizational skills, rare in a developing country. An American adviser to the Kenya Government once said that Mboya was the only minister in Kenya who had the ability to fill a cabinet post in Washington. He had the hardest job in the Kenya cabinet, running the ministry that coordinates all of Kenya’s foreign assistance and tries to insure that its economic growth remains orderly and constant.

Perhaps more significant, Mboya was always called upon by fellow cabinet members, even those who disliked him, to push unpopular legislation through parliament, to defend them against embarrassing attacks, and to organize their election campaigns. The government may founder without him.

Finally, Mboya was an irreplaceable salesman for Kenya. In his many trips abroad, he always seemed to make his audience feel that he was one of them. Despite all the depressing news about  Africa, he somehow managed to inspire confidence in the continent. His death shatters that image. Kenya, with an economy dependent on tourism and foreign investment, will surely suffer. And so will Africa.

Mr. Meisler is the Africa correspondent of the Los Angeles Times.