Facing mountain of woes. Ruthless drug traffickers and political violence are tearing apart South America's oldest democracy. A four-part series explores how Colombia, a key US ally, is fighting back.

Latin America's oldest democracy is in danger of coming apart at the seams. Colombia is under siege from one of the world's most virulent home-grown drug networks as well as a rising tide of political violence that threatens to set off a civil war.

The country's turmoil bodes ill for the United States in several ways. It could undercut Colombian democracy, striking a blow to the spread of civilian, pluralistic rule throughout Latin America - a trend the US supports. Also, the growing drug problem tests the ability of the US and its Western Hemisphere allies to contain a scourge that is already straining US-Latin American relations. Finally, Colombia has strategic importance, since it sits just south of Panama and the canal.

``Even more than Mexico, Colombia is the country closest to Central America - and the Panama Canal - that has the greatest chance of destabilizing,'' says Juan Tokatlian, director of international studies at the University of the Andes.

The two-year-old government of President Virgilio Barco Vargas seems unable to corner any of the major narcotraficantes or halt the political killings and disappearances that some say are reminiscent of Argentina's tragic ``dirty war'' of the early 1980s. And it finds itself besieged as well by critics from the United States - including US senators who, frustrated by the ceaseless flow of ``coke'' onto US streets, threaten to send in US troops.

Colombians resent US declarations that they are not doing enough to defeat the drug traffickers. ``When a Colombian official is killed by the drug mafia, then they say this country is run by traffickers,'' Mr. Tokatlian says. ``But isn't it just the opposite? The fact that people are dying means they are putting up a fight.''

Colombia's drug barons, said to control production and distribution of about 80 percent of the cocaine that flows into the US, have in the past four years carried on a war of assassination and intimidation against law enforcement and judicial officials, and anti-trafficker journalists and politicians.

They have joined forces with leftist guerrillas and right-wing death squads to protect their assets and eliminate their foes.

A longtime close ally of the US, Colombia is only now getting the attention of most Americans, because of the drug issue.

``Colombia hasn't aroused the interest of the United States because this country hasn't been a problem,'' Tokatlian says. ``Now that things are getting worse here, we're starting to get some attention up there.''

In fact, Colombia has been a clear exception to the almost general rule of Latin American economies in dire straits which have captured public attention in recent years. While Mexico, Brazil, Argentina, Peru, and others have struggled with almost unmanageable foreign debt problems, Colombia's economy has harvested the fruit of wise fiscal policies (as well as benefited from the wealth of the illegal drug trade).

Although the debt has grown from $6 billion in 1980 to $15 billion in 1987, fiscally prudent Colombia has managed its foreign obligations well and is considered one of the best credit risks in Latin America.

Economic growth has averaged over 5 percent in the past two years. Exports, once based almost solely on coffee, now include flowers, bananas, petroleum, and coal.

One example of confidence in the economy is the intent of US investors to increase their stake in the booming Colombian energy industry.

But the vibrant economy has worked largely to the benefit of a few. Nearly 1 of every 2 Colombians still lives below the poverty line.

The nation's largely democratic history (with some interruptions), now in its 103rd year, is the story of a power balance between two political parties tightly controlled by the nation's elite. The deep, widespread poverty and the unwillingness until recently to open up the political system have spawned a level of political violence unknown in almost any other country.

Colombia has the continent's oldest guerrilla insurgency, which began in the 1960s. A presidential effort to open the political system by means of an amnesty in 1984 led to the formation of a new political party by the guerrillas. Since then, some 500 of that party's members, including winning candidates, have been killed by death squads. The death squads, many claim, are manned or permitted by Colombia's armed forces. The guerrillas themselves are battling back, and the toll is rising on both sides.

In 1986, Colombia had the highest per capita ratio of murders in the world for a nation not at war. The violence and chronic poverty are spurring more and more Colombians to flee the country - many to the US. Close to 1 million now live in New York, Miami, and Los Angeles.

Yet most Colombians say they would prefer to stay in their own country. They are proud of their democratic history, reputation for hard work, and rich cultural heritage. Home to Nobel prize-winning novelist Gabriel Garc'ia M'arquez and internationally acclaimed painter Fernando Botero, Colombia has a flourishing arts community in provincial capitals as well as in Bogot'a, known as the ``Athens of Latin America.''

Colombians say their nation is a far cry from the image they see painted in the foreign press of a corrupted nation controlled by a criminal conspiracy. They resent what they see as ``the gringos'' - a derogatory term seen more and more often in newspaper headlines here - wanting to blame their drug problem on someone else.

If anti-Yankee sentiment is starting to simmer in Colombia, it will be something relatively new. Even when US President Theodore Roosevelt engineered Panama's secession from Colombia to pave the way for the US to build the Panama Canal, Bogot'a harbored little ill will. Since then, it has stayed close to the US. Military ties have been strong for decades.

Out of the 100 members of the nonaligned movement, Colombia was fourth in voting with US positions in international forums, according to a 1986 State Department study.

Nor has foreign debt strained relations between the two countries. The US has been pleased by President Barco's indifference toward Latin American initiatives to unite debtor nations and by his resistance to opposition pressures to refinance the debt.

But with the capture and subsequent release of drug cartel kingpin Jorge Luis Ochoa in November, Colombia's close ties with the US started to unravel. The US felt it had had a pledge from Colombia to keep Mr. Ochoa behind bars until he could be extradited. Extradition has been the keystone of Washington's effort to break the cartel's power. Six weeks after Ochoa's arrest, his attorneys obtained a court order that allowed him to walk out of a Bogot'a jail. The US responded by delaying entrance visas to Colombian travelers and holding up perishable Colombian exports.

A crisis developed until the US ambassador to Colombia, Charles Gillespie, managed to calm the stir in Washington and get US Customs to narrow its reach to selective targets. Looking back, Ambassador Gillespie sees the affair in a positive light. It helped, he says, push Bogot'a and Washington toward ``a more effective collaboration in fighting this scourge.''

[Reuters reports that Colombia's highest administrative court ruled Tuesday there was no legal basis to extradite Colombian citizens to the US.]

Although US politicians still flail away at the shortcomings of Colombia's antidrug efforts, Bogot'a believes Washington has become more understanding.

``I think both sides are ready for a new strategy,'' says a Cabinet minister, who asked to remain unnamed. ``We haven't reached an agreement, but the mood is toward a new focus on the problem.''

First in a four-part series. Next: The war against drugs.