By JUAN FOREROLA COOPERATIVA, Venezuela — More than ever, Colombia's 39-year-old civil war is spreading beyond its porous borders, bringing to its five neighbors a troubling brew of armed leftist rebels, right-wing death squads, drugs and refugees.

Increasingly, the guerrillas have set up camps and the drug traffickers used by both sides to support their forces have opened transport corridors through isolated
jungles in other countries as a Washington-backed drug eradication program in Colombia has intensified. The refugee problem is also spilling over, with more than
300,000 Colombians having crossed into Ecuador, Panama and Venezuela in the last four years, according to United Nations estimates that have not been publicly
released.

The problems are most pronounced here in Venezuela, where a 1,400-mile border has become a flash point between the left-leaning government of President Hugo
Chávez and its ideological opposite in Colombia under President Álvaro Uribe.

The complications were obvious on a recent day in this hamlet just inside Venezuela. Just miles from a Venezuelan military base, a ragtag band of about 10 Colombian
rebels took a break, supremely at ease as they lolled on makeshift beds, their Kalashnikov assault rifles hung from wooden posts. They swatted mosquitoes as they
chatted with their first foreign visitors.

"We are here because the people wanted us here, so we have come," said the commander, who identified himself as José. He was referring to the rebels of the
Revolutionary Armed Forces of Colombia, who became a regular presence here four years ago and have been increasingly welcomed by poor Venezuelans and
Colombian refugees.

In late March, with the world focused on the war in Iraq, Venezuelan military aircraft bombed and strafed this outpost. The target was not the leftist rebels, who
regard Mr. Chávez as something of a hero, but the Colombian paramilitary group that had pursued the guerrillas across the border.

Colombian officials and Venezuelan opposition leaders condemned the bombing as an intervention by Mr. Chávez in Colombia's war. Venezuela angrily rejected the
criticism, saying Colombia had failed to control its borders and allowed both sides to bring their conflict across the scarcely patrolled frontier.

José, the rebel commander, predictably took Mr. Chávez's side. "They were defending themselves, and their sovereignty," he said of the Venezuelan government,
which he called "revolutionary, just like us."

After the bombing, the paramilitaries fled back across the Gold River into Colombia. Refugees and high-ranking Colombian officials said the Venezuelans continued to
strafe them, firing into Colombian territory.

The bombing and strafing are signs of a new intensity in the spread of the civil conflict and led to a hasty meeting in April between Mr. Chávez and Mr. Uribe, who
promised to work together.

In recent months, vast fields of Colombian coca, the tropical plant that yields cocaine, have been sprayed from the air and destroyed. In response, growers and
traffickers have relied increasingly on border areas — in some cases, in other countries — to plant and transport illegal crops and drugs, Colombian and United
Nations officials say.

In turn, the guerrillas and paramilitary groups — both classified as terrorist organizations by the United States State Department — intrude, fighting over control of the
crops, the drug trafficking corridors and the field hands needed for harvesting.

In Brazil, according to recent Colombian military intelligence reports, the guerrillas are forming a new unit in Brazil that would traffic drugs, arms and, possibly,
precious goods like gold. In April, the government of President Mireya Moscoso of Panama deported 109 Colombian refugees — 63 of them children — whom it
accused of being rebels, violating international covenants regarding the treatment of refugees, the United Nations said.

In Ecuador, rebel camps have been discovered in regions where drug trafficking is common.

Venezuela, however, has been the most affected. According to Colombian intelligence reports and Venezuelan landowners, Colombian guerrillas kidnap ranchers,
extort money from businessmen and traffic in drugs. Colombian intelligence reports also say that the rebels have set up temporary camps in at least three Venezuelan
states, eluding Colombian forces and their de facto paramilitary allies.

"It is an area that allows them to rest, to reorganize and regain momentum to again come back into this country," a high-ranking Colombian military officer said in a
telephone interview.

Venezuelan landowners and merchants who live along the border have accused the Venezuelan military of ignoring or colluding with rebels. It is unclear whether that is
government policy, but United Nations officials, Venezuelan farmers and aid groups report that Venezuelan military units have tolerated the rebels for years.

"I believe they have a policy that they will not attack the guerrillas if the guerrillas do not attack them," said a senior United Nations official who works on border
issues. "The Venezuelan military does not have a belligerent policy toward Colombian guerrillas."

The Venezuelan government denies partisanship. It has 20,000 troops along the frontier, and will send 4,000 more, officials say. "It is not true what they say," said the
commander of a marine patrol on the Gold River. "We repel both of them, the guerrillas and the paramilitaries."

In La Fría, a cattle town just south of here, however, the presence of guerrillas has drawn in paramilitary units. As in Colombia, where they are financed by
landowners to fight the rebels, the paramilitary forces have offered landowners here the same services. Several ranchers in La Fría reported three meetings this year
between Colombian paramilitary groups and merchants and landowners.

"If they eliminate the rebels, that is a favor to me because it resolves my problems," said a 60-year-old La Fría rancher. "If they invite me to a meeting, I will go
because I need to get out from under this problem."

The leader of the La Fría ranchers' group, Jorge Méndez, said he opposed the paramilitaries but understood why some might turn to them for help. "The military do
not have the ability to act," he said, "and there may be a policy from the government not to act."

Though the Venezuelan government blamed the Colombians for the problems, some Venezuelan Army officers were openly disdainful of the ranchers here.

"If they invested in benefits, in health care, in the workers, no one would bother them," said Col. José Vásquez, the second in command of the Venezuelan Army units
here, adding that he was speaking for himself, not the army. "But as long as cattlemen just earn and earn and earn, they will have their problems."

The leftist presence here dates back to 1999, when Colombian paramilitary units began a strong offensive against the leftists, and the rebels fled to "get a beachhead in
Venezuelan territory," said Alfredo Rangel, a former consultant to the Colombian Army.

Since then, for the poor along the border, particularly the Colombian refugees, the guerrillas have become an accepted, even welcome, presence.

"They are the ones who watch after the civilians," said Mary González, standing in the charred remains of a school, a pharmacy, a cantina and a food pantry that were
burned during the paramilitary attack on La Cooperativa.

She said the paramilitary forces shot and killed several people. Then she smiled as she recounted how Venezuelan aircraft then came screaming out of the sky to
bomb the members of the paramilitary group.

"They chased them all the way to the other side and hit them there," she said. "There were not even any bones left. The bombs hit them so hard."