San Juan, Puerto Rico:-Now it is Puerto Rican terrorists who may pose a threat to President Reagan's life, according to intelligence officers here and judging by public evidence. Unlike Muammar Qaddafi's hitmen, as U.S. citizen the Puerto Ricans need not risk crossing boarders since they are already here. Also, they are indistinguishable from millions of other Puerto Ricans and Hispanics living stateside and thus can move about freely.

Furthermore, the Puerto Rican terrorists are as well-trained and as fanatical and reckless as their Libyan or other foreign counterparts.

They have announced publicly their intention to "get" the President and top aides in a recent speech by their reputed "godfather," 72-year-old Juan Antonio Corretjer (the last syllable s pronounced like the German guttural "ch"). A revolutionary firebrand for half a century, Corretjer, lauding 11 members of the Armed Forces of National Liberation (FALN) found guilty of seditious conspiracy by a federal jury in Chicago, charged President Reagan personally with "bribing" and "torturing" one of them, Alfredo Mendez, into betraying his comrades. He then thundered:

"Who deserves contempt? Who deserves punishment? Poor Alfredo Mendez? No! The President of the United States, the CIA chiefs, the warden of Pontiac [Ill.] prison, the public prosecutors Margolis and Sullivan in the federal office of the Chicago district attorney, and the detectives and police of Chicago!"

The President is"humanity's worst enemy," Corretjer pronounced.

Intelligence officers here regard the Corretjer speech as a call to Puerto Rican terrorists to literally "punish" the President and the law enforcement officials involved in prosecuting the FALN "Chicago 11." a case still on the books. There is more than ample evidence of acts of vengeance committed by them over the years.

In December 1979, three terrorist groups ambushed a U.S. Navy bus en route to Sabana Seca Communications Center, near this capital city, shooting two petty officers to death and wounding 10 other naval personnel. In a communique they issued taking responsibility for the attack, the terrorists said they were avenging the alleged murder of a comrade, Angel Rodriguez Cristobal, who was found hanging in a Tallahassee, Fla., prison cell and listed a "suicide." Corretjer exulted, after the sailors were killed, "his [Rodriguez Crisobal's] death is avenged."

Only last January, the same three terrorist groups - the Macheteros, Armed Forces of Popular Resistance (FARP), and Organization of Volunteers for the Puerto Rican Revolution (OVRP) - joined in firebombing nine Air National Guard jets worth $45 million at Isla Verde Air Base, also near San Juan. This was a deliberately selected military target in their ongoing "people's war of national liberation" against "Yankee imperialism."

The writer has seen a Macheteros-produced videotape of preparations for the firebombing, which was carried out in only seven minutes, 40 seconds - ample testimony of the terrorists' high level of precision and efficiency.

Since 1975, Puerto Rican terrorist groups have perpetrated 260 acts of violence on the island, according to official count. These range from bombings of banks, post offices and U.S. business enterprises to blowing up electric power plants and assaulting military installations and personnel. An estimated 70 or more violent attacks were committed on the mainland during the same period, mostly by the FALN. Federal authorities have revived their investigations into 31 unsolved bombings in New York City alone, based on new information supplied by Alfredo Mendez.

The FALN in the only Puerto Rican group operating in "enemy territory" -as Corretjer characterizes the continental United States - and would probably be the logical one entrusted with forming a hit squad to "get" the President and other important U.S. officials. Formed in 1974 to open a "second front of armed struggle for Puerto Rican national liberation" - the first "front" being of course the island itself - the FALN has demonstrated its fanaticism and daring numerous times.

Thus it opened the "second front"with five bombings of prominent Manhattan locations, including Rockefeller Center, on the very same day, Oct. 26, 1974.

Mere weeks later, it killed a policeman in reprisal for the alleged murder of a Puerto Rican activist poet "by the racist New York Police Department."

Perhaps the FALN's most notorious act was the bombing of historic Fraunces Tavern in lower Manhattan, in January 2975, killing four and injuring more than 60 persons.

In March 1980, armed FALN members seized President Carter's campaign headquarters in Chicago and GOP presidential candidate George Bush's in New York City, on the same day. Eleven of the band were caught in Evanston Ill., three weeks later, and all have been sentenced to long prison terms. Only one, Alfredo Mendez, admitted FALN membership, apparently hoping to get his 75-year sentence reduced.

Another suspect in the Chicago case, and perhaps the most dangerous of the lot since he is the FALN's bomb-making expert, William Morales, is currently a fugitive.

U.S. intelligence officers believe the FALN was "connected " with the robbery in October of a Brink's armored truck near Nyack, N.Y., by Weather Underground and black terrorists in which two policemen and a guard were killed. The FBI's No.2 man in New York, Kenneth P. Walton, has stated that the join Federal-New York City Terrorism Task Force he heads is looking into possible links with the FALN and "possibly some foreign organizations" as well.

The "foreign organizations" are regarded by intelligence source to mean Cuba's General Intelligence Directorate, or DGI, Fidel Castro's worldwide espionage service whose principal aim is to destabilize the United States. Puerto Rico is high on the DGI's destabilization target list.

The "father of the FALN," and in a sense of Puerto Rico's modern terrorist movement, is a 42-year-old Puerto Rican agent of Cuban intelligence who is wanted in Puerto Rico for jumping $2,000 bail, Filiberto Inocencio Ojeda Rios. He founded and led the very first of Puerto Rico's new terrorist groups, the Independent Armed Revolutionary Movement (MIRA), in 1967. MIRA members received training and arms in Cuba and became operational in early 1969, when they bombed a police station, destroying two police cars, a bank and other enterprises.

After many bombings - 35 alone in New York City during 1970 - MIRA was finally broken up by the police and Ojeda arrested. After jumping bail, he headed for New York, got assigned to the DGI contingent attached to Cuba's United Nations Mission, and formed the FALN with old MIRA members as the nucleus.

Although wanted by the Puerto Rican police, Ojeda, a master of disguise, slips in and out of the island undetected. On one of his last known visits in 1979, he joined Corretjer and another old comrade in unifying Puerto Rico's five principal terrorist groups under a single command - repeating the pattern of Cuban insistence on the unity of armed revolutionary factions followed in Central America. Under the unified command, known as the CRN, come the FALN, the Macheteros - whose formal name is the Boricua Popular Army (after the island's Indian name, Borinquen) - the FARP, OVRP, and People's Revolutionary Commados (CRP).

Over the Puerto Rican Unified command is a Cuban organism, the Coordinating Revolutionary Junta (JCR), based in Havana, whose Eastern Caribbean section is headed by Ojeda. The virtually unknown JCR was set up jointly by the DGI and the Cuban Communist party's national liberation-intelligence unit, the Americas Department, and it provides arms, training and guidance to revolutionary organizations throughout Latin America, including Nicaragua's Sandinistas and El Salvador's guerrillas.

Other "foreign organizations" with which Puerto Rican terrorists may be connected include the PLO and the band around the infamous "Carlos the Jackal" - born Ilich Ramirez in Venezuela - with which Ojeda made contact during a stint for the JCR in Paris before moving to Havana.

Ties have long existed between the FALN and other Puerto Rican extremist groups and the Weather Underground. Corretjer, for one, acknowledged such ties in an interview, and added that he fully sympathizes with the Brink's attackers. He also revealed that his Puerto Rican Socialist League, an "open" Marxist-Leninist organization, maintains contact with U.S. black extremists and some Chicanos in Colorado.

Still another island Marxist-Leninist group with ties to the Weather Underground is the Puerto Rican Socialist Party.

The Puerto Rican Socialist party (PSP) has maintained a quasi-diplomatic "mission" in a house in Havana's luxurious Vedado section for many years, its secretary general, Juan Mari Bras, told this writer. Since the PSP pays no rent, nor presumably staff upkeep, the "mission" is virtually subsidized by Castro.

Mari Bras makes fine distinctions between "terrorism," which he eschews, and "armed struggle," which he frankly embraces, yet local intelligence sources say he organized one of the earliest terrorist groups, the Armed Commandos of Liberation (CAL), in 1965. He did so, they add, using the pseudonym "Alfonso Beal," the surname a compound of two independence heroes, Betances and Albizu. CAL members received guerrilla training and arms in Cuba and committed many acts of violence, including the bombing of a U.S. Governors Conference in San Juan, until its disappearance in 1972 or 1973.

Mari Bras also bears some responsibility for the organization of Filiberto Ojeda's MIRA, the FALN's predecessor, through a pro-independence movement which subsequently became the PSP. The PSP, in turn, supplied 600 Cuba-trained youths to various terrorist groups following its abysmal showing in the 1976 gubernatorial elections, causing them to abandon the electoral route to independence preached by Mari Bras after 1970 and to embrace "urban guerrilla warfare."

No fewer than nine terrorist groups have proliferated in Puerto Rico over the past 15 years - an average of about one per every 400,000 inhabitants -and that incredible total may be incomplete. Nor does it include legal, "open" support groups such as the Socialist League, PSP, and above all the Federation of Pro Independence University Students (FUPI), which is celebrating 25 years of existence as the chief spawning ground of Puerto Rico's far-left revolutionaries.

FUPI is, for example, the guiding force behind a Marxist-led University of Puerto Rico student strike which has been going on since the beginning of the school year and has precipitated rioting and other violence on the campus; that, in turn, has compelled Gov. Carlos Romero Barcelo to send police units to occupy the university on two occasions - thus providing the extremists, of course, with another issue: "repression."

Another terrorist breeding ground is the electrical workers union, UTIER, which is also Communist-controlled and recently conducted a protracted strike that strained Puerto Rico's energy facilities. Concurrently, the Macheteros and other outright terrorist groups backed the UTIER strike with a series of bombings of power plants, causing at least half-a-dozen blackouts in San Juan during November alone.

Although contemporary Puerto Rican terrorism was born during the relatively prosperous mid-1960s, the past year has seen a record rise in violent acts which may be attributed in part to widening discontent over a sharp decline in the island's economy. Unemployment is at 21 per cent of the labor force, and a massive 38.2 per cent of youths between the ages of 20 and 24 - providing a growing pool of potential troublemakers.

Inflation is around 11 percent and expected to rise even higher as imports of needed products approach double the island's exports. Such classic exports as sugar are all but disappearing because Puerto Rico can no longer produce them economically; consequently, sugar production has plummeted and so has employment in the industry.

The economic crunch is expected next October, the beginning of fiscal year 1983, when federal food and nutrition assistance may be cut by 25 per cent.

The Commonwealth status they have enjoyed since 1952, and was once hailed as a "showcase" of democracy for other Caribbean countries, is now perceived by many Puerto Ricans to be an economic failure. But the alternative of statehood, advocated by Gov. Romero's New Progressive Party, is supported by only 45 per cent of the people and is seen by the rest as worse economically - since island residents would be subject to state taxes and less federal aid - while endangering their Spanish cultural heritage.

Although the pro-independence forces - the non-leftist Puerto Rican Independence Party and the Communist PSP - polled less than 6 per cent of the vote in the 1980 gubernatorial election, independence retains a mystique for Puerto Ricans and is potentially an explosive issue. Cuba, seeing an opportunity to pursue its destabilization plan, has accordingly made itself the champion of Puerto Rican independence in the United Nations. Seeking U.N. recognition of Puerto Rico as a U.S. "colony" which should be "liberated from Yankee imperialism," it has managed to get the island's "colonial" status placed on the General Assembly's 1982 agenda.

The United States is thus truly faced with a two front war over Puerto Rico: the diplomatic one in the United Nations led by Cuba and backed by the Third World as well as the island's extremists, and the terrorist front, which has lately assumed the character of what the terrorists themselves term interchangeably a "people's war" or "urban guerrilla warfare." The principal target, too, has changed, and is now military. Thus the attacks on Sabana Seca Communications Center and Isle Verde Air Base.

"We want to get rid of every imperialist military installation on this island," Corretjer told me flatly, adding that he and his supporter will go to every length to attain their objective.

Cuba, of course, is fully in accord with that, aware of Puerto Rico' strategic importance in the Caribbean. Some 60 per cent of all our imported oil is shipped through the Caribbean, and such major naval installations as Roosevelt Roads in Puerto Rico may become decisive if Washington embarks on an all-out effort to interdict the flow of arms and military forces from Cuba and other Soviet-bloc countries to Cental American guerrillas.

Aiding the Puerto Rican terrorist in the long run is the violence endemic to the island. Our highest leaders have not been immune to that phenomenon. In 1950, the nation was shocked when members of the Nationalist party tried to assassinate President Harry Truman, and again in 1954 when they shot up the House of Representatives, wounding five congressmen. Four of the Nationalists involved in those attempts were released from federal prison only two years ago, and today enjoy their freedom in Puerto Rico entirely unrepentant. Lolita Lebron, perhaps the most famous of them, has unashamedly declared: "We have done nothing to cause us to repent."

And she adds, ominously:

"I cannot disavow people who use bombs. I hate bombs but we might have to use them."

Lebron's fanaticism, engendered bu the Nationalist leader and hero Pedro Albizu Campos, who attempted an insurrection on the island in 1950 coinciding with the attack on Truman, has infected the current crop of Puerto Rican terrorists. They have, moreover, wedded Albizu Campo's wholly indigenous nationalism to Marxism-Leninism and gladly accept the material and political support of the powerful Soviet Union and such client-states as Cuba. That implies an abundance of material resources and sophisticated techniques now available to his successors.

It may also suggest that the Libyan threat to President Reagan could conceivably be executed not by Libyan assassins but, rather, by Puerto Rican counterparts believing in the same ideological objectives.