Nicaragua Intensifies War Against Contras : Sandinistas Seek to Seal Infiltration Routes, Bring Conflict Under Control by End of Year

MANAGUA, Nicaragua —  Fortified with newly diversified troop units and a willingness to risk conflicts with neighboring countries, Nicaragua’s army is in the midst of an all-out effort to seal off the infiltration routes of anti-Sandinista rebels that begin in Honduras and Costa Rica, its neighbors to the north and south.

The campaign, now in its sixth month, has met with some success. In the north, a high-priority region for the government, the rebels, called contras , have been cut off from the rich, coffee-growing mountains where they operated last year.

Supply lines from rebel bases in Honduras have lengthened as the contras are forced to make end runs around Sandinista outposts.

Battle for Foothold

In the south, Sandinista troops were battling as late as Friday to gain a firm foothold on the San Juan River along the Costa Rican border and choke off jungle trails.

The strategy is part of a Nicaraguan government plan to bring the contra conflict under control by the end of the year.

“The border campaign is costly, to be sure,” said Joaquin Cuadra, the Sandinista vice minister of defense. “But it is much more costly if we have to keep fighting the invaders deep inside the country.”

Foreign observers in Managua describe the current fighting as the Sandinistas’ most intense counterinsurgency campaign in more than three years of fighting the contras, reflecting the need felt to bring an end to the bloodshed and the high economic cost of the insurgency.

“The Sandinistas are learning how to fight this war,” a Western diplomat said. “They have increased their ability to use artillery and special counterinsurgency forces.

“They want to make the insurgents seem like losers.”

While fighting persists in Nicaragua, debate in Washington continues over whether to renew U.S. aid to the contras. The Reagan Administration is seeking $14 million in aid for the rebels this year and $24 million for fiscal 1986. The Senate has approved an aid package that would exclude weapons and ammunition, and the issue is expected to come up in the House this week.

The Sandinistas are using three types of troops in their offensive. The special Sandinista forces, the so-called Irregular War Battalions, carry the fight to the rebels by dispersing into small bands and mirroring contra tactics. The new static territorial battalions hold down terrain abandoned by the rebels. And reserve units man the heights along infiltration routes.

It is not clear how many Sandinista troops are fighting or have been deployed in the widely separated battlefronts. Some estimates range as high as 60,000.

As the conflict approached both borders, tense encounters with Honduran and Costa Rican frontier forces occurred. Sandinista troops have pursued rebels across both international boundary lines.

Combat in recent weeks left two Honduran soldiers dead in the north and two Costa Rican Civil Guardsmen killed in the south.

Cross-Border Flights

Last week, the Nicaraguan government claimed to have downed three unmarked, American-made, UH-1 helicopters that the Sandinistas said strayed over Nicaraguan territory from Honduras.

Sandinista officials are concerned about the border incidents, feeling that they might lead the United States to intervene on behalf of either country but especially Costa Rica, which has no army of its own, only a rural police force.

“Hitting Costa Rica is like raping a child,” Cuadra, the Sandinista vice minister of defense, said. “Costa Rica’s reputation is all innocence.”

Rebels from the north countered the Sandinista border campaign by hiking through rough country into east-central Nicaragua, where there are daily reports of fighting.

Contras Attack Port

These guerrillas belong to the Nicaraguan Democratic Force, largest of the contra groups. They have penetrated as far south as Boaco province in the east-central zone, and in May, they peppered the Caribbean port of Bluefields with gunfire.

“We consider that attack as a diversion, an attempt to lure us away from the border,” Cuadra said.

The bulk of recent fighting has taken place in the sparsely populated province of Zelaya and in eastern Jinotega and Matagalpa provinces.

Sandinista reports say that the contras, in classic guerrilla fashion, operate only in small groups.

The Sandinista drive coincided with supply problems for the contras, who until last summer, were directly supported by the United States through the CIA.

The cut-off of that aid, mandated by Congress, created uncertainty among rebel leaders. Contra forces were pulled back into Honduras from Nicaragua, making it easier for the Sandinistas to occupy key, high-ground positions on the frontier.

More recently, troubles between the rebels and their hosts in Honduras resulted in another distraction. Border tensions prompted the Honduran armed forces to demand that the contras move their bases deeper inside Honduras. The move further stretched the contras’ infiltration and supply routes.

“On the bright side for the contras is that they seemed to have survived supply problems,” a Western diplomat said. “They are not disintegrating.”

Nicaraguan military officials say that the first and most important target of the Sandinista army’s thrust has been the lushly mountainous northern zone from the town of Esteli northeast to San Rafael del Norte, Pantasma and Quilali and north to the border.

The area is populous, and Sandinista farm policies and attitudes toward religion had created disenchantment among conservative farmers there.

“These are areas of maximum contra influence,” Cuadra said.

Besides pouring troops into the north, the Sandinistas evacuated remote villages in which the residents were known to be sympathetic to the contras. The farmers were resettled in camps, and government troops destroyed some of their homes.

To secure the zone, the Sandinistas trained troops native to the mountains to serve in the territorial battalions. The mountain youths are expected to be both familiar with the terrain and less unpopular with local residents, who were offended by occupying outsiders.

“When the contras left, they had sympathizers and an information and supply network,” Cuadra said. “If they come back, they’ll find empty villages and Sandinista troops.”

The same strategy is being put into effect in the southern zone near Costa Rica. There, the Sandinistas moved remote villagers into government camps as long as two years ago. However, until last week, they never attempted to occupy the tangled jungles on the banks of the San Juan River.

“We want to cut off the flow of troops into southern Nicaragua,” Cuadra said. “We want to clog their lungs.”

Bombing Raid Recorded

Newspapers in Managua have published pictures of Sandinista bombing raids over a rebel camp at La Penca on the banks of the San Juan, which flows eastward into the Caribbean from Lake Nicaragua parallel to Nicaragua’s border with Costa Rica. The rare bombing, by propeller-driven planes, was apparently a prelude to a ground assault Friday.

Rebels of the Revolutionary Democratic Alliance, headed by former Sandinista commander Eden Pastora, have clung to the river as their main escape route into Costa Rica.