(The author spent two months this summer in Nigeria with Operation Crossroads Africa. He worked on the costruction of an open-air market in Ojo Village, twenty miles northwest of the capital of Lagos.)

THE BRUTAL civil war in Nigeria is slowly dragging to a close. Little remains of the secessionist Eastern Region--Biafra. In just a few months, probably, all rebel territory will belong to the Federal Republic. Even then, though, some fighting will continue. Guerrilla units are operating behind federal lines, and they have been since August.

These guerrillas will survive a few months, perhaps, after the capture of all rebel territory. Fear will move them and keep them dodging and fighting against a better-equipped and larger enemy. The rebel Ibo are convinced that defeat means death, both for soldier and civilian, but despite their desperate defense, death will come, as it has for most of their people.

In the political confusion after independence in 1960, political parties became firmly associated with regional and tribal groupings. In July, 1966, a group of army officers, dominated by members of the Hausa tribe, overthrew a federal government led by Ibo officers. Thus, when in September between thirty and forty thousand Ibos were killed in massive anti-Ibo riots in Hausa territory, the association between the massacres and government policy seemed obvious to leaders among the Ibo. Odumegwu Ojukwu, then the Governor of East Central State, which is Ibo, issued a call for all his tribesmen to return to the safety of their Eastern homeland, deported all non-Ibos, and seceded in May, 1967.

In the grisly drama of the war -- the atrocities, the starving masses, the jungle fighting -- rational thinking is overwhelmed by emotionalism. In the Western world cries of outraged morality for the arsenal of the press and public. The crisis in Nigerian seems a clear-cut case of the good guys versus the bad guys. The massacres in the North justify the Ibo cause and condemn the Lagos government. With self-righteous verbal overkill, defenders of Biafra cry that Lagos is waging a war of genocide.

WHILE THE WAR has its roots in tribalism, the baffling political history of Nigeria makes it impossible to point a finger of guilt at any particular group. When the British carved out their colonial empire in West Africa, they paid little attention to anything but economic and administrative expediency. Nigeria is an uneasy marriage of over two hundred tribal groupings, many with linked histories and cultural similarities, others with very different roots and ways of living. The Hausa-Fulani with about 29 million tribesmen dominate the North. Islam is their faith, and they trace their origins to the North and East of Africa.

The Yorubas in the West are largely Protestant and Catholic, and number about 9 million. The religious mixture of the Ibos in the East is about the same, but there are 12 million of them. Another five or six million Nigerians comprise a myriad of smaller tribes.

The three powerful groups--Hausa, Yoruba, and Ibo--have formed the major parties. Governments rose to power when two parties aligned against the other, and fell when the coalition dissolved and allegiances shifted.

After independence, though, a Yoruba-Ibo alliance coalesced into a single party opposing the Hausa. The numerical superiority of the North was one spur for the coalition, and, in fact, despite the coalition, the Hausa won a massive victory in the '64 elections.

The coalition, though, rested on more than a fear of numerical inferiority. Cultural differences heightened tribal suspicions.

According to the stereoyptes, Hausaman is religious, often illiterate, and traditional. Iboman is clever, hardworking, and ambitious; Yorubaman happy, sensitive, and warm.

THE stereotypes are, of course, just images, but the images are not entirely exaggerated. For both cultural and historical reasons, the North is the least developed section of the country. The bulk of the Nigerian army before the crisis was Hausa; for the uneducated the army is a road to advancement.

The Ibos in Nigerian history were a relatively insignificant tribe, but their society had achievement-based norms that adopted quickly to Westernization. All over Nigeria they formed a merchant and professional class. An engineer said, "If you are a businessman and you need engineers, you read applications and you don't look at tribes. Fifteen of the twenty men you hire will be Ibos."

The Yorubas fall somewhere in between, but closer to the Ibos than the Hausas. They are literate; they're politically sophisticated, but they look at life with a grin.

Thus, the Yoruba and Ibo came together not so much because they feared the numerical preponderance of the Hausa, for it would have been more politically expedient for either group to make peace with the Hausa against the other, but because they feared the political dominance of an uneducated majority. They could see the resources of the East and West financing the development of the North, and they envisioned hordes of inefficient Hausa bureaucrats.

This kind of friction--educated versus uneducated--is not new. In 1953 the Yoruba party called for independence after three years. The Ibos supported the demand, but the Northern group opposed and defeated it, well aware that independence in 1966 would mean economic and administrative subservience to its more developed neighbors.

The propaganda arms of the Ibo and Yoruba party labelled the Hausa traitors and stooges of the British, while in the North rioting between the feuding groups broke out.

In 1953 the British mediated the feuds; after independence they were unchecked. The Hausa government elected in 1964 amidst cries of foul play was topped by an Ibo-led coup in January, '66. The new government which had seized power to "clean up the country" did so with a vengeance, and the deaths of former Hausa leaders sparked riots and unrest in the North.

Then came the July coup, when Hausa officers struck back and installed a Tiv tribesman, Yakubu Gowon, as head of the military government. Some say that Gowon came to power because he was regarded as a man with an even temper and no strong personal ambition. Others said that in the tribal politics of Nigeria, Gowon held an ace, for his tribe dominates the artillery corps.

Whatever the reason, the compromise candidate could not hold Nigeria together. He tried. After the Ibo massacres, he offered concessions, but whatever he did was interpreted by Governor Ojukwu as one more sign of duplicity and hatred. On the one hand, it seemed, Gowon offered friendship, while on the other, the people he governed murdered Ibos. Gow- on was caught. Only punishing the Hausa mobs involved in the riots would have placated Ojukwu, but to punish Hausas when the bulk of the army was Hausa would have been political suicide.

Gowon also has to deal with Hausa-Yoruba feuds that even the war emergency has not laid to rest. Observers, some with government jobs and official contacts, have said that when the Ibos seceded, the Yorubas would have gone with them, but Yorubaland was quickly occupied by the Nigerian army.

Government printing centers publish enormous amounts of propaganda, most of it directed against Ojukwu, but a recent broadside from the Ministry of Information in a northern city attacked the pretentious inellectuals of southern groups (Yoruba and Ibo).

It reads: "Events have always proved these 'intellectuals' not only wrong, but blind and ignorant tools of prejudice. They still masquerade about in Universities brandishing intellectualism which they equate with Ph.D. but do not prove by thinking properly."

Looking at Nigeria's history, particularly the past twenty years, the outbreak of war isn't surprising. That same broadside which criticized "southern intellectuals" admitted that the country had been divided for a long time: "It is clear," the article said, "that the 'Nigeria' which was forged by the British was a purely artificial creation comprising three main groups which had very little in common apart from their dark skins."

Yet everywhere there is a feeling of indignation and surprise that the Ibos had actually seceded and started a dirty civil war. It was irrational. It must have been the work of a madman, many Nigerians feel, and they blame Ojukwu. The press often compares him to Hitler.

Just how many government officials really believe this version of events is impossible to tell. However, it is a very dangerous line of thinking, for it implies that all evil will disappear once the devil is gone. With that idea, the army presses on, and people look to the surrender or death of Ojukwu as the end of Nigeria's troubles.

Peace will, of course, just mark the beginning of Nigeria's real difficulties, because instead of waging a relatively easy war, the government will be facing staggering problems of redevelopment, relocation, rehabilitation. And the old spectre of triablism will draw strength from the inflamed passions of war.

Yet, when you walk the streets of Lagos, you have to look hard for signs of war. True, between radio and T.V. shows sinister-sounding announcers say, "Challenge anyone doing anything suspicious. Save precious lives. Save Lagos from destruction." But everyone has heard those lines so often that they've become the butt of innumerable jokes.

At 7 p.m., traffic in and out of Lagos State is closed by soldiers at checkpoints. Originally, the measure was intended to cut the flow of infiltrators. Traffic within the city goes all night, though, and Lagos night-clubs are uninhibited.

Lagos is a cosmopolitan city, and like any growing capital, the new and old exist side by side. In one of the open-air markets you bargain; in one of the big department stores you pay a flat rate for a sundae or a sweater. Just a few miles outside the city, the University of Lagos is literally rising out of jungle forest.

The war is far away to the east, and so life in Lagos goes on as usual, apparently. Even young men have no worries, for the federal army is entirely voluntary. In fact, government propaganda points to Ojukwu's use of conscription as one more sign of his evil nature.

But there is a conflict in the West. It's quiet and personal.