Peru, Ecuador Battle on Small but Deadly Scale : Latin America: As peace talks hit snag, platoon-size units continue war in Amazon rain forest.

In the border conflict between Ecuador and Peru, small columns of specially trained jungle fighters from both sides move through the same rugged and heavily forested terrain where there are no front lines, no massed troops. Platoon-size units of 30 to 40 soldiers clash, and when their skirmish ends, they fade back into the forest.

“They’re intermingled in the jungle,” one military analyst said.

Peruvian forces are trying to expel Ecuadorean troops from a disputed border area around the headwaters of the Cenepa River. The fighting, which began Jan. 26, has been concentrated in that rough patch of ridges, dense rain forest and rushing streams.

Patrolling units have clashed repeatedly. Peruvian helicopter gunships have rocketed Ecuadorean positions. Ecuadorean ground-to-air rockets have downed at least two of the choppers. As the fighting goes on, diplomats attempt to negotiate a cease-fire agreement.

A week of talks hit a new snag Tuesday after Ecuador proposed what it called minor amendments to a draft cease-fire agreement--a pact that already had been accepted by Peru. Peruvian negotiator Eduardo Ponce called the Ecuadorean proposal “inadmissible.”

The talks had been suspended Sunday in Rio de Janeiro after mediators submitted the latest cease-fire proposal. As both countries prepared to resume talks in Brasilia, the Brazilian capital, Peru’s reaction apparently stalled negotiations again.

So far, the fighting also appears to have resulted in a standoff. Although bigger Peru has at least double the military strength of Ecuador, analysts say, the Ecuadoreans have held their ground thanks to these advantages:

* Ecuador’s army controls the Cordillera del Condor, a steep mountain range west of the Cenepa River. This key terrain, dominating the combat zone below, gives Ecuadorean forces a superior vantage point.

* Ecuador supplies its fighting forces by roads over the Cordillera del Condor, while Peru must use long-distance helicopter airlifts.

* The rugged jungle terrain, together with low clouds and heavy rainfall, keep Peru’s superior air power from effectively supporting ground troops.

* Ecuadorean troops are well entrenched. Before the fighting began, they had dug defense emplacements and planted land mines around their bases.

One military analyst estimated that the fighting is between ground forces of no more than 200 troops on each side around the Cenepa River headwaters. Ecuador also has reported Peruvian air attacks on Ecuadorean border posts outside the contested area.

Ecuador reported Tuesday that its casualties so far are 11 dead and 26 wounded, while Peru has acknowledged 22 dead and wounded. Some unconfirmed news reports have put the combined death toll at more than 100.

For years, both sides had considered the disputed 50-mile section of border a neutral zone, and overlapping patrols from each side often met without conflict. In fact, officers from the two sides routinely got together for talks.

Peru now asserts that Ecuador began turning patrol bases into permanent detachments. Peru says it is fighting to eject Ecuador from bases called Base Sur, Cueva de los Tayos and Tiwinza. Ecuador says those have been permanent detachments for years.

Peru maintains that the border should be marked north of Cueva de los Tayos and Base Sur. That would leave Ecuador without access to the Cenepa, a tributary of the upper Amazon River. Ecuador says it will not give up access to the Cenepa as part of its historic claim to Amazon Basin territory.

Describing the fighting as “very much like parts of Vietnam” combat, a military expert said: “Ecuador can hold out for a long time.”

“Clearly Ecuador holds the key terrain,” the expert said. “I know they have sufficient firepower so that if they really wanted to take out the Peruvians they could do so.”

Ecuadorean analysts say Peru is unlikely to use its superior military force to widen the conflict into a full-scale border war. Stiff Ecuadorean resistance in a wider war would increase Peru’s costs and casualties, they say, undermining popular support for President Alberto Fujimori, who is running for reelection April 9.

The cease-fire agreement proposed by mediators over the weekend called for the withdrawal of Peru’s troops to a Peruvian post called Soldado Pastor on the southwest side of the combat zone. Ecuadorean troops would withdraw to a post called Coangos, about six miles to the northeast.

Under the proposal, the combat area would become a demilitarized zone, supervised by an international observer force. Assistant Secretary of State Alexander Watson, who helped mediate the Rio negotiations, said Tuesday in Washington that the observer force would include “military people and I think perhaps some civilians as well.”

“We and the other three guarantor countries have indicated that we are willing to send observers into this region to observe and verify the separation of forces and the demilitarization, if you will, of this area,” Watson said in a press briefing.