The assasination of South Korean President Park Chung Hee was the product -- at least in part -- of deep rivalries in the country's security apparatus that Park himself fostered.

"The irony is positively Shakespearean," said Gregory Henderson, a prominent specialists on Korea. "Park was consumed by that which he nourished killed by the system he created."

Kim Jae Kyu, director of the Korean Central Intellidence Agency who murdered Park Friday, began his barrage of bullets by slaying Cha Ji Chul, the head of the presidential protective service who, Kim believed, was blocking his access to the president.

Henderson and other academic and State Department experts noted that Park actively encouraged competition between two top aides like the KCIA's Kim and bodygaurd Cha.

The KCIA has been the most powerful agency in South Korea since it was founded after Park took power in 1961. Combining the powers of the CIA abroad and the FBI and a secret police at home, its agents have long controlled every aspect of Korean life.

But Henderson notes that since Park gave himself great powers in the Yushin Constitution is 1972, there has been an "immense struggle" to gain access to the president. In recent months, it appears, Kim Jae Kyu was becoming convinced that Cha was turning against him.

Korean government officials have announced that Kin killed Park and Cha because of fears he would lose his job in the wake of inept government handling of recent student uprisings and the dismissal of the opposition party chief.

Park had dismissed KCIAchiefs in the past at times of political crisis. In 1973, he fired Lee Hu Rak, after a commotion about the KCIA kidnaping of a Park political rival, Kim Dae Jung.

In 1976, Park fired KCIA boss Shin Jik Soo when the South Korean influence-buying scheme in Congress was exposed.

E. Baker, a Korean language and history expert for a recent congressional investigation of U.S. Korean relations, noted yesterday that Park dismilssed top government officials to ensure that none gained enough of a power base to challenge him for power.

As a result, State Department officials here agree, there is no clear No. 2 man set to emerge as the next leader of Korea. Park "created a vacuum, he made sure there was no real No.2" one State Department official said.

The rivalry between the KCIA chief and the head of the presidential protective force goes back at least to the 1960s. Kim Hyung Uk, head of the KCIA from 1963 to 1969 until he was fired, told a congressional hearing in 1977 that he was a longtime rival of Park Chong Kyu.

Park Chong Kyu headed the president's personal security service until he resigned in 1974, after accepting the blame for failing to prevent the death of Mrs. Park Chung Hee in an assassination attempt on the president.

Though the palace bodyguards seemed to be controlling access to Park in recent times, the KCIA has played a much larger and more important role in Korean affairs historically.

Kim Jong Pil, a principal planner of the coup, founded the KCIA, later founding Park Chung Hee's political party. At the start, a corps of Army intelligence personnel made up the KCIA. But now there are estimates that it has as many as 300,000 employes.

Kim Hyung Uk, who headed the KCIA longer than any other, was denounced as a traitor to his country when he testified before a House committee about help he gave to Washington socialite Tongson Park to help lobby for continued U.S. aid.

Kim disappeared early this month while on a visit to Paris, and his family and some U.S. officials believe he may have been kidnaped by the KCIA.

Evidence during the congressional investigations of Korean lobbying showed that the Park Chung Hee government changed its tactics in the United States in the early 1970s. For years, KCIA officers at the embassy and consulates here harrassed Korean-Americans who voiced opposition to the Park regime.

The KCIA influence-buying campaign in Congress was a response to Korean fears the United States would cut off aid in protest to Park's growing repression of civil rights in Korea.

By 1975, the number of KCIA agents in the embassy in Washington had doubled. But by the end of the year, American intelligence reports of attempted bribery of U.S. congressmen had triggered investigations that embarrassed the Park regime and damaged relations with the United States.

In Korea, meanwhile, the KCIA continued its all-encompassing presence. Reporters who visited were told to expect their phones would be tapped and their hotel rooms bugged. Dissident leaders recalled how their personal KCIA officer would stop by before appointments just to let them know the government was watching their visits.

The assassination of Park by the KCIA director has thrown a cloud over the future of the agency. Sources in Seoul reported that the South Korean military has virtually taken control of the agency.

One of the key unanswered questions about the murders is the survival of Kim Kye Won, chief secretary of the Blue House staff, who was spared in Kim Jae Kyu's hail of gunfire.

Kim Kye Won was himself director of the KCIA from 1969 to 1970. according to Henderson, a former professor at the Fletcher School of Law and Diplomacy in Boston, the two Kims were classmates of Park from military training school and were close personally.

Kim Kye Won is said to have been the official who reported Kim Jae Kyu's deeds to the military authorities.