The seizure of the embassy of the Dominican Republic here Wednesday appears to have been an act of desperation rather than a demonstration of strength on the part of the M-19 guerrillas.

In the view of many observers here, including Defense Minister Luis Carlos Camacho Leyva, who has overall charge of Colombia's internal security, the April 1. Movement (M-19) was virtually eliminated as a coordinated and active urban guerrilla force last year after secret military police arrested and jailed more than 200 suspected members.

The movement is Colombia's most notorious leftist group and consists mostly of alienated sons and daughters of prominent families. Often highly educated, the guerrillas are seeking to accelerate what they see as the inevitable collapse of a society alleged to be corrupted in favor of the wealthy.

April 19 is the date in 1970 that populist former dictator Gustavo Rojas Pinilla lost his electoral bid for the presidency. The revolutionaries who founded M-19 some four years later shared the widespread view that Rojas was defrauded. However, M-19 is not thought to have any connection with the less radical movement of the late dictator, now headed by his daughter, Maria Eugenia.

In an interview less than 48 hours before the M-19 guerrillas seized the embassy, capturing 15 ambassadors and as many as 65 others, Camacho Leyva had said "the situation [with respect to the M-19] has changed fundamentally in the government's favor."

In retrospect, the assessment appears to have been overly optimistic but it was virtually confirmed by Commander No. 1, the leader of the guerrillas holding the embassy, in a telephone interview with a Bogota newspaper published yesterday.

Commander No. 1 acknowledged the M-19 had been badly hurt by last years arrests which came after a spectacular raid on a military arsenal here that netted the M-19 more than 4,500 weapons.

"Yes, it was a hard blow but not total," he said, "The proff is this operation,"

The guerrilla leader said the most important of the guerrillas' demands was the release of 311 political prisoners held as a result of last year's counterguerrilla campaign. At least 200 to the 311 are suspected M-19 members.

"After a dialogue with the government it might be possible to modify, in part, some of the demands, but the principal one is the liberation of the political prisoners," he said. "Our compact is to succeed or die."

According to diplomats with access to intelligence reports on the M-19, the 200 m-19 guerrillas now in jail form the heart of the urban guerrilla organization, which is said to have 400 to 500 members. It is generally believed that many of the M-19's besttrained activists are now under arrest.

Thus, the embassy takeover is viewed by some analysts as a desperate stand to recover lost comrades and keep the six-year-old force from crumbling.

If the prisoners are not released as a result of the most daring guerrilla raid in Colombian history, the chances that the M-19 will be able to regenerate itself soon are considered highly uncertain.

The stakes are also high for the government of President Julio Cesar Turbay Ayala, who came to power in 1978 promising to restore law and order, and reduce the violence associated with common crime and drug trafficking as well as guerrilla warfare.

Colombia has at least four major guerrilla organizations in its cities and rural areas and an ever richer and more violent drug "mafia" along its Caribbean coast. Bogota's rates of street crime and kidnapings for ransom are among the highest in the world.

If Turbay gives in to the M-19's demands to release the 311 political prisoners, his effort to restore "security," blostered by a tough National Security Act he approved in 1978, would be in ruins. the guerrillas, however, already have demonstrated that they are prepared to kill to achieve their aims.

According to Enrique Santos Calderon, publisher of Bogota's leftist Alternativa magazine, the M-19 members have restored to armed revolution because of "a feeling of impotence and disillusionment" with Colombia's monolithic two-party political system.

Successive Liberal and Conservative Party governments have failed, in Santo's view, to alleviate dire poverty, stem increasing inflation, provide decent schools and housing, or redistribute income. Workers and peasants, courted at election time often are then largely forgotten. Santos is himself a son of a prominent Bogota publishing family.

The M-19 is leftist but not avowedly communist, and is considered more idealistic and humanitarian than the other three Marxist revolutionary groups -- the Armed Revolutionary Force jof Colombia (FARC in Spanish initials), the National Liberation Army (ELN) and the workers' Self-Defense Movement (MAO).

Costa Rican Ambassador Maria Elena Chaussoul Monge, one of the female hostages released by the M-19 yesterday, said she was impressed by the women guerrillas with whom she talked.

"They impressed me by their culture," Chaussoul Monge said." They spoke to me of Neruda [Pablo Neruda, Chile's late Nobel prize-winning poet], they spoke to me of different systems of government without making leftist propaganda and without disparaging democratic systems."

The M-19's tactics resemble those of Uruguay's Tupamaros, who undertook in the late 1960s to embarrass the then democratic government by unmasking corruption and hypocrisy. The Uruguayan Army later defeated the Tupamaros. c

The M-19 began in 1974 by placing catchy ads in Bogota's major newspapers, with such phrases as "Lack energy? Inactive? Wait for the M-19." A flare the publicity has been characteristic of the group.

An early revolutionary act was to seize liberator Simon Bolivar's sword from a museum in Bogota, a highly symbolic gesture that did far more to embarrass the government than to threaten its control over the country. In January of last year, the M-19 executed its well-planned raid on a mulitary arsenal in Bogota by tunneling into the arms storage area and seizing the thousands of guns without being detected. The weapons eventually were recovered by the government.

The tunneling operations humiliated the military, leading to the crackdown that resulted in the arrests of the 200 suspected M-19 activists and other guerrillas.

If those comrades are freed, the M-19 will once again be seen as having armed forces, knocking another prop from under the institutions that now govern Columbia.