(For a multimedia presentation on the changing drug war, see http://www.reuters.com/news/globalcoverage/drugTrafficking) By Patrick Markey BUENAVENTURA, Colombia, July 20 (Reuters) - Colombia's most infamous cocaine lords have been killed or jailed, violence has fallen sharply and drug seizures are at an all-time high. But the string of successes in the world's No. 1 producer has not been enough to slash the amount of cocaine for sale on the streets of the United States or Europe. Even as the U.S.-backed war on drugs has tamed top cartels, smaller groups have emerged, shifting coca leaf to areas that are harder to fumigate and opening new smuggling routes. Colombia's Pacific coast is now a key battleground. "This is one of the heaviest trafficking zones," said Lt. Juan Correa, patrolling in a U.S.-made Piranha gunboat in search of speedboats carrying drugs and guns near the large port of Buenaventura. "They use all the rivers in speedboats, and use the mangroves for improvised factories. Then they take the drugs out into the open sea to larger ships," he said. Days earlier, Colombian Marines waded chest deep through a jungle river an hour's helicopter ride away and found 6.5 tonnes of cocaine buried in the earth and waiting for shipment out into the Pacific Ocean. It was the latest major seizure in a security crackdown that has won President Alvaro Uribe strong approval ratings at home and the full support of U.S. President George W. Bush. Marines make daily captures of cocaine, drug-making chemicals and weapons in the rivers and impoverished wooden slums around the harbor here, where traffickers, rebel groups and paramilitaries all battle for control of smuggling routes. Since 2000, the United States has pumped more than $4 billion in mostly narcotics and security aid into its Plan Colombia program to slash cocaine shipments and curb Latin America's oldest guerrilla insurgency. It says the money helped rescue Colombia and clearly much has changed from the late 1980s, when drug lord Pablo Escobar unleashed a wave of bombing and shooting attacks that killed hundreds of police, government officials and civilians. A ruthless man who portrayed himself as a friend of the poor and opened a zoo on his ranch featuring giraffes, rhinos and hippos, Escobar was shot dead in a police chase across the rooftops of Medellin in December 1993. Since then, both the Medellin and the rival Cali cartels have been devastated by arrests and extraditions. Uribe's government has sent hundreds of drug traffickers to face U.S. justice since he took office in 2002, and the military has retaken large areas once held by Marxist guerrillas also involved in the cocaine trade. "The country is much stronger institutionally to contain drug trafficking, and in that Plan Colombia has achieved a purpose," top police chief Gen. Oscar Naranjo told Reuters. 'COULD SLIDE BACK' But it was also supposed to slash the flow of cocaine to the United States, and there it has failed, experts say. United Nations figures show Colombia's cocaine output is steady at around 600 tonnes a year, or more than 60 percent of world supply. Despite a jump in seizures, the U.S. government concedes there has been no major long-term impact on the availability or price of cocaine on U.S. streets. "We underestimated the difficulties when we started Plan Colombia, I will grant you that. But I think we have come a long way and if we cut this now, we could slide back," said a top U.S.Embassy official in Bogota. "This wasn't going to be finished in five years." Democrats, who control of the U.S. Congress, are questioning Plan Colombia's record and the White House's attempts to extend the largest U.S. aid package outside the Middle East. Some want to slash funds for coca fumigation in favor of programs encouraging farmers in impoverished rural areas to grow other crops. "Fumigation has proved able to reduce coca-growing in a specific zone for a specific period of time. But outside that zone and even in the same zone after the spray planes go elsewhere coca cultivation always increases," said Adam Isacson at the Center for International Policy in Washington. Uribe warns that cutting fumigation aid now could trigger an increase in coca production even as his government plans more social spending in areas once abandoned by the state. His allies insist the country would be in much worse shape and cocaine output higher if it were not for Plan Colombia. "If we hadn't fumigated, Colombia could have 250,000 hectares of coca," Vice President Francisco Santos said recently. "Nothing competes with coca. It is so profitable and we must see that as a reality we face." Around Buenaventura, several key traffickers and FARC rebel leaders have been captured in the last few weeks, but the war goes on. A string of bomb attacks on the port that killed two people and wounded 23 more last month were attributed to the FARC trying to gain more control. "Drug trafficking is a high profitable business," said Col. Hector Aguas, the marine commander in Buenaventura. "That gives people the push to keep trying it."
