Robert Kagan served as assistant secretary of state for Latin American affairs during the Reagan administration, and he regards U.S. support for the contras as essential to the eventual triumph of democracy in Nicaragua in 1990. But this book is more than an apologia for that policy. An insider’s unvarnished account, it recalls the adage that if one likes sausage, one should not inquire too closely about how it is made. Kagan argues persuasively that the decision-making process was "chaotic, lurching, changeable, and often inherently contradictory."

Initially, Kagan writes, Reagan’s policymakers were no more eager to "get tough" with the Sandinistas than Jimmy Carter had been. They decided with some reluctance to support the contras only after several diplomatic overtures had failed. At first, their goal was limited to pressuring the regime not to aid the rebels in El Salvador. But as the contras grew in number and strength, an incipient split within the administration widened between the "conservatives," who saw the contras as a force for expelling the Sandinistas, and the "pragmatists," who insisted that the contras were a political liability. During this battle, which lasted until well into Reagan’s second term, the Sandinistas learned to their frustration that the policy’s only durable element was agreement between the White House and a shifting congressional majority that the contra option should be retained as insurance that the Sandinistas would keep promises made at the negotiating table.

Kagan regards this policy of limited aid to the contras as a necessary but not sufficient condition for the Sandinistas’ eventual demise. Military pressure alone would not have sufficed either to topple them or to force them into elections. But combined with other factors—the Sandinistas’ mismanagement of the Nicaraguan economy, growing diplomatic isolation, and doubts about sustained Soviet support—contra aid sharply narrowed the regime’s options. By 1989, the Sandinistas came to see free elections as the only way they could keep power, but by then it was too late. Throughout the 1980s they had passed up too many opportunities to make peace on terms that would have saved their revolution. In the end, Kagan notes, they were "their own executioners."

Regrettably, several hundred pages of unnecessary detail make A Twilight Struggle one of those books that would have been twice as good at half the length. And it is curious to see this former Reagan administration official use certain phrases without apparent irony—such as "North American aggression" and (for U.S. encouragement of democratic elections) "hegemony." Nevertheless, this is an impressive achievement that will surely become the standard work on a troubled chapter in U.S. foreign policy.