COMPANERO: The Life and Death of Che Guevara.<i> By Jorge G. Castaneda</i> . <i> Alfred A. Knopf: 352 pp., $30</i>

Why, Jorge Castaneda asks at the start of “Companero,” did the Bolivian army wash the bullet-ridden corpse of Che Guevara and pose it, open-eyed, seemingly unmarked and serene? The image, flashed around the world in 1967, became an icon: a revolutionary Deposition from the Cross for the generational insurgencies that were breaking out in such different places as the United States, Paris, Prague and Latin America.

For sheer deadness, a photograph of the corpse in all its bloody indignity would have done better. It could even have been arranged to suggest that Guevara was killed in combat rather than executed (something apparently opposed by the CIA advisor). Perhaps, Castaneda implies, there was an old warrior tradition at work: To dignify your foe is to dignify your victory.

Begun with a provocative reflection, Castaneda’s biographical examination of Che Guevara continues that way. It is a search and a self-search, troubled and magisterial at the same time. It is an exercise of the heart and the mind, penetrating enough to reach an impressive conclusion but not glib enough to rejoice in it or to tidy away all signs of its author’s struggle.

Castaneda, a Mexican and one of Latin America’s leading political historians, lived a part of Guevara’s journey. He has deplored the shadow of United States hegemony, particularly in its more naked years: not so much out of ideology--his is relatively liberal and pragmatic in Latin American terms--but because of its distorting effect on its neighbors.

He is alive to the appeal of Guevara’s extraordinary qualities: the energy, the quixotic incorruptibility, the dream that sheer revolutionary willpower can change the world and the inconvenient moments of objectivity and sardonic humor that hiccup inside the dream. At the same time, he brilliantly documents his own chilly verdict on the harm done by a heroic will--and on the stupidity that corrupts it--when it substitutes itself for the reality it operates in.

It is a reluctant verdict, in some ways, but Castaneda’s reluctance, allied with his unsparing intelligence, makes “Companero” outstanding in a year that has seen two other considerable books on the subject. One is the excellent, massively detailed “Che,” by Jon Lee Anderson; the other, “Guevara, Also Known as Che,” by Paco Ignacio Taibo, whose valuable original material--some shared with and handsomely acknowledged by Castaneda--is unsteadily written and thought out.

Shorter than either of these, “Companero” wields detail where it counts. Some of Castaneda’s interviews are unique and notably revealing, but he is immune to the journalist’s and researcher’s temptation to use material because he has discovered it. What we needed, in this year of vast publication, is not more facts about Guevara but an intelligence that reflects on them and puts them in a context.

Castaneda moves relatively quickly, though vividly, through Guevara’s earlier life: his upper middle-class Argentine upbringing in a quirky, politically leftist family; his Beatnik-style wanderings through Latin America; his radicalization in Guatemala, where he observed the United States-backed overthrow of the mildly left-wing Arbenz government; his meeting and joining with Fidel and Raul Castro in Mexico; and the frail botched landing aboard a rickety tub below the Sierra Maestra in Cuba.

Frailty turned to spectacular success. Originally enlisted as the expedition’s doctor, Guevara fought with a bravery and discipline that led Castro to put him in charge of the column that crossed Cuba to win a decisive victory, after a fearful 45-day Long March, in the strategic town of Santa Clara.

The achievement would disastrously form the basis for Guevara’s military adventures in the Congo and Bolivia in the mid-’60s after his intransigent radicalism found itself isolated in Cuba. Castro had chosen, pressed by American hostility, in part--but it was a choice--to incorporate Cuba into the Soviet bloc. Unconditionally pro-Moscow at the start (he approved of the Hungary invasion), Guevara came to realize that the Russians had no use for world revolution and that they would relegate Cuba to the same role it had had with the United States: supplier of sugar.

Guevara had run the Central Bank and the Industry Ministry with enormous revolutionary zeal. (Nobody should earn more than $350 a month, he decreed, until it was pointed out that this would be hard on the secretaries, who were already earning more.) But if Moscow was going to bail out Cuba, Guevara’s schemes for building an industrial nation by offering the workers moral, not monetary, incentives would have to go.

Castaneda portrays, vividly and subtly, the complex relations between Castro and Guevara at this difficult time. “Neither marriage nor divorce,” Guevara described them to a friend. Castro indulged and protected his comrade to the end--or almost to the end: There is controversy as to why he failed to attempt a rescue mission in Bolivia.

Whether it was incitement, encouragement or simply consent--Castaneda makes the ambiguity fascinating--the Cuban leader found it safer for Guevara to foment revolutions abroad than trouble at home. In 1965, Guevara and his 120 Cuban soldiers, chosen for their African descent, stagnated for seven months on the eastern shore of Lake Tanganyika waiting vainly for the rival Congolese rebel leaders (among them Laurent Kabila) to show up. There were one or two sorties; Guevara sulked and read and eventually Castro ordered an evacuation.

After a clandestine return to Cuba and more arguing with Castro, Guevara and a small group of volunteers established themselves in late 1966 on a farm in southeastern Bolivia. Nobody wanted them there: The Bolivian Communist Party was opposed, the Russians were furious and threatening and, most humiliatingly, not a single peasant joined. On the contrary, they helped the army. The end came within a year, after great suffering--Guevara struggled with dysentery and his chronically acute asthma--and several brief engagements. Most of Guevara’s party were captured or killed, and a couple of dozen Bolivian soldiers died.

Castaneda’s analysis is lucid and absorbing. Guevara’s theory--that a “foco,” or nucleus, of guerrillas could, by fighting the army, bring down retaliation on the population and create its own support--rested on a misread example. In Cuba, an urban network was working, the Sierra Maestra peasants had been prepared, the opposition parties helped in the fight and there were funds and political support from the middle class. (When Guevara was felled with asthma in the Sierra Maestra, medicine was sent up from the nearby town of Manzanillo.) In the Congo and Bolivia, none of this existed.

Furthermore, the author points out, there had already been a revolution in Bolivia. There had been elections and a land reform. The original left-wing rulers had come to some accommodation with the United States. The army was populist as well as nationalist and to the peasants, if the soldiers weren’t exactly theirs, they were a lot more theirs than a band of clueless Cubans.

History is tragic, even the second time around; but it’s hard not to see the ironies. Guevara’s political assumptions in Bolivia were a mirror image of American assumptions in Vietnam and the Bay of Pigs. Surely revolution (or democracy) is better. Surely the Bolivians and Congolese (or the Vietnamese and Cubans) will realize it, even if some have to be killed.

As for Guevara’s icon image, there are some two dozen icons missing here. The ones with Indian features, the dead Bolivian conscripts, never did get themselves postered in college dormitories nor sold on beer mugs, either.