SOFT-SPOKEN Colombian President Cesar Gaviria Trujillo, like most of the 23 heads of state at last week's Ibero-American summit, found himself overshadowed by the star power of Cuban dictator Fidel Castro.But while Mr. Castro was the big draw for hordes of reporters, it is the low-key Mr. Gaviria who seems to represent the region's political and economic future. Colombia's youngest president, surrounded by young advisers, is one of Latin America's new pragmatists. And Gaviria has gained a reputation for doing what he says he will do. With an approval rating of over 80 percent at home, Gaviria has, in little less than a year in office, moved many in his violence-torn country from despair to hope, convinced key drug traffickers to surrender, and brought a halt to narco-terrorist bombings. The country has a new Constitution, and a new political movement - including former rebels - is developing . But Colombia experts in the US and in Bogota say Gaviria still has his work cut out for him. Guerrilla war and human rights abuses, often the work of death squads, continue. The society remains immersed in the cocaine culture. Once-warm relations with the United States have the potential to frost over if Colombia's drug war loses intensity. But in a Monitor interview Gaviria said the country's reformed political structure, the upcoming trials of drug cartel bosses, and peace talks with guerrilla leaders make this year a potential watershed for his country. "It's a critical moment in Colombian history," he says. "We are really solving the more complex problems the country had. We are finding new political ways for democracy in Colombia. We are leaving behind the problems of narco-terrorism." Another of the most intransigent problems, guerrilla war, also seems to be yielding. Four smaller rebel groups have turned in their weapons, and the 8,000-man Revolutionary Armed Forces of Colombia (FARC) and the National Liberation Army (ELN) are talking peace with the government, in part because of political changes included in the new constitution. "Without a doubt, the great success of [Gaviria's] one year in office is presiding over the peaceful transition to a new constitution - that, and getting the guerrillas to the peace talks," says Marc Chernick, assistant director of the Institute of Latin American and Iberian Studies at Columbia University. President Gaviria has a clear sense of what he still hopes to accomplish. "The main goals are those of solving this culture of violence in Colombia," he says. "And that depends a lot on how we can strengthen the judiciary.... That's a very important goal." Much hangs on the judicial system, the effectiveness of which has been compromised by death threats, corruption, and assassinations. The system now faces its biggest challenge: the trial of Pablo Escobar and other Medellin cartel leaders. Close ties between the US and Colombia have frayed in the past year because of a Colombian policy of no extradition and leniency promised to cartel leaders in return for their surrender. "No, I don't think we have a difference of views with the US government," Gaviria says. "I think they are cautious, waiting for the results we get.... On interdiction and law enforcement we have the same objectives." But Colombia's controversial policy could set a precedent for other drug-producing countries. Bolivian officials announced June 22 that they would adopt a policy similar to Colombia's. Of additional concern to the US is the intensity with which Colombia pursues cartel leaders other than those of Medellin, who directed the narco-terrorist bombings and assassinations that spurred the new policy. Primarily, the rival Cali cartel's powerful, but so-far-less-violent bosses worry US officials. Gaviria seems willing to direct the Army and police to pursue the Cali cartel with the same intensity, but is unsure of the outcome. "The policy against the cartel of Cali is just the same as the policy against the cartel of Medellin," Gaviria says. "We hope we will have the capacity to dismantle the cartel of Cali as we have done with the cartel of Medellin." At the same time, Colombians stress the need to reduce the demand for drugs, as well as their supply. Gaviria also sees some hope here. "We are encouraged by the information we have that the demand is coming down somewhat in the United States," Gaviria says. "We are worried about hearing that demand is going up in Europe and Japan." Beyond the drug challenge lies the guerrilla war, which continues to damage the economy and provoke rightist death-squad activity. Gaviria considers a peace settlement his prime objective. "They [the guerrillas] are asking for some political changes, which we don't think are difficult to get," Gaviria says. "We hope we can then give them the guarantees they need to [enter] political life." But while the FARC and the ELN are talking peace, obstacles such as military reform remain. Clara Lopez, a Bogota city council woman and Harvard-trained economist, links the guerrilla war to a growing number of paramilitary groups, citing a recent Amnesty International report that 138 paramilitary groups are in operation. "We still have a dirty war going on," she says. Ms. Lopez says rightist death squads will continue killing because constitutional reform did not address military reform. But Gaviria seems unconcerned. "We are sure that the armed forces of Colombia are really the allies of the peace process.... This [military] reform is not necessary to find peace," Gaviria says. "We still have a lot of important goals to achieve," he says. "The most important of all, of course, is the final settlement with the guerillas, which is very important for political life. The ending of this kind of violence in Colombia is very important."