[The Reaper]

Mass Arrests

Complementing its attack against the FARC in the countryside, Colombia also hit the ELN in the cities with the help of U.S. intelligence.

According to Colombian sources, a U.S. intelligence officer set up a
listening post inside the 18th Brigade's headquarters.

The U.S. began sharing cellular phone and radio frequencies with the military and the special prosecutor's office to pinpoint rebels and their collaborators.

"One of the reasons for success has been their intelligence," said Gen. Carlos Lemus, head of the 18th Brigade and the man responsible for pipeline security. "This is also part of the American aid we are receiving."

Besides helping the army fight rebel units, intelligence from wiretaps and radio interceptions became important in gathering evidence for the prosecutor to order a series of arrests.

The first were in October 2002, followed by more in November, and the next April and August. Another round, in October 2003, came just three days before municipal elections. More than 200 people were charged with being linked to the guerrillas. At least 40 were freed for lack of evidence. A few were convicted. Most remain in jail pending trial.

Local politicians and human rights activists said the detentions, including those of union leaders, human rights workers, journalists, elected officials and political candidates, were politically motivated.

One detainee was Jose Murillo, the leader of the area's best-known human rights group. Another was a priest, Father Jose Helmer Muñoz, the leading candidate for governor and a frequent critic of the government's hard-line policies. A third man, Antonio Jose Ortega, won election as Saravena's mayor despite being in jail.

Few in the province deny meeting with the guerrillas, but they insist that they did nothing wrong. With no state presence, the guerrillas were the law.

Despite the heavy military presence, right-wing paramilitaries, illegal private armies dedicated to wiping out the guerrillas, have moved into the area. Left-wing critics of the authorities have been killed. Arauca now has one of the highest homicide rates in Colombia, which has one of the highest homicide rates in the world.

"We have to coexist in the middle of four different groups, the ELN, the FARC, the paramilitaries and now the government," said Arianis Barrera, whose husband was arrested while he was running for mayor. "It is totally traumatic."

But Juan Hernando Poveda, the tough-talking prosecutor, said the arrests were justified. He showed The Times seized documents that included correspondence in which a former governor sent guerrilla leaders a detailed list of the oil royalty payments he had sent them. Another document had the former governor addressing a guerrilla leader by his first name: "Dear Pablo," the communication began.

"The ELN has infiltrated everything - politics, economics and social
spheres," Poveda said. "But we find them. Rats lie down with rats."

Satisfaction

Whether the operation was a success remains unclear.

Pipeline attacks are down - but they began declining before the U.S. effort started with the arrival of the Special Forces trainers. After a high of 170 attacks in 2001, the pipeline was hit 36 times in 2002 and 34 times in 2003. So far this year, there have been just five attacks - one of the lowest numbers in the pipeline's history.

Instead, rebels began blowing up the electrical towers that provide the power for Oxy's pumps. But those attacks also have dropped off this year.

"We have taken important steps, steps never before taken," Lemus said. "But there's still a lot left to do."

On a helicopter ride between Arauca and Saravena, a U.S. Special Forces crew flew over the main Occidental compound, only a few yards from Colombia's border with Venezuela.

Huge clouds of steam rose from the plant, appearing as low, massive thunderheads looming over glinting rivers and green prairie.

The Special Forces company commander said he had no problem putting his life at risk to protect the oil pipeline.

"The Colombian government and its infrastructure is very important for the stability of the state, which ultimately is important to the stability of the U.S.," he said, shouting over the thump of the blades overhead.

"Whatever the infrastructure - oil or whatever - if it supports the
government here, it adds stability to a region that is important for the United States."

Times special correspondent Ruth Morris in Colombia and researcher Mark Madden in Washington contributed to this report.