Nicaragua: What Comes Next? : A TWILIGHT STRUGGLE: American Power and Nicaragua, 1977-1990.<i> By Robert Kagan (The Free Press: $37.50, 903 pp.)</i>

When Violeta Barrios de Chamorro won Nicaragua’s 1990 presidential election, many observers hoped her moderate policies would heal the nation’s historic rifts and usher in a new era of peace and prosperity. But as the campaign to choose her successor draws to a close this month, it’s clear that the nation she will hand over is little better than the one she inherited.

Nicaragua remains the second-poorest country in the hemisphere and virtually all measurable indices of the country’s well-being--literacy, infant-mortality rates, disease, unemployment--are streaking in the wrong direction. Even Chamorro’s widely hailed success in formally ending the Contra war has been mitigated by the fact that armed bands continue to operate in the northern mountains.

Amid this continuing turmoil, it’s not surprising that the favorites in the Oct. 20 election are throwbacks to Nicaragua’s past: ultra-conservative Arnoldo Aleman, an old-style caudillo in the tradition of the former dictator Somoza, and one-time President Daniel Ortega, a leader of the Cuban-style Sandinista revolution that overthrew the Somoza regime.

For Robert Kagan, a former member of the State Department’s policy planning staff under President Ronald Reagan, this outcome was inevitable. In his conclusion to “Twilight Struggle: American Power and Nicaragua, 1977-1990,” Kagan suggests that the U.S. must adopt a more consistent foreign policy to help stabilize Nicaragua. To be sure, direct military intervention has been tried; the U.S. has invaded Nicaragua more frequently than any other Latin American country. But those interventions have been followed by long periods of disinterest on the part of Washington, leading Kagan to conclude that “to steer a country like Nicaragua along a steady course toward democracy . . . would seem to require something other than spasmodic interventions followed by hasty withdrawals.”

By charting this history and then illustrating the forces that drove America’s Nicaraguan policy from presidents Jimmy Carter through George Bush, Kagan goes a long way toward explaining the nation’s current unrest. His analysis will be suspect to some, by virtue of his fidelity to Reagan’s Central American policies. Indeed, Kagan gives short shrift to the Reagan administration’s controversial mining of Nicaragua’s harbors, and he doesn’t explore persistent rumors linking the Contras to drug smuggling. He does, however, mention the Contras’ proclivity for human rights abuses.

There is no shortage of books criticizing U.S. policy in Nicaragua from the left, but there are comparatively fewer from the right. Kagan’s title fleshes out the ranks and, despite its drawbacks, makes us care about what happens to Nicaragua after Chamorro leaves office.