Viewing North Korea not only as a military threat, but also a diplomatic rival, South Korea strove to prevent its major allies from increasing exchanges with the North three decades ago, Seoul’s declassified diplomatic papers showed Monday.

Following the assassination of its authoritarian strongman Park Chung-hee in 1979, Seoul went through a rough period in the early 1980s, striving to prevent diplomatic fallout with Japan and the U.S. while remaining wary of another invasion by Pyongyang.

According to the diplomatic dossiers, Seoul had received reports from outside intelligence officials that increased military activity ― similar to that taken ahead of the three-year Korean War in 1950 ― was being detected in Pyongyang.

Although neither side broke the truce, the Seoul government was highly sensitive about the U.S. and Japan increasing direct contact with the communist North, and also strove to appease former war enemy China, the papers showed.

Such disclosures were to be revealed Monday as part of the Foreign Ministry’s annual release of diplomatic documents after 30 years of confidentiality.

Seoul made an official complaint to Washington following a trail of trips by high-ranking U.S. officials to North Korea in 1980.

The U.S. government should not have permitted the visit to Pyongyang by its congressman Stephen Solarz and State Department spokesman Thomas Reston, South Korea said.

Feeling the need to improve ties with China to keep Pyongyang in check, the South Korean government also began to positively review the issue of calling China by its official name “The People’s Republic of China” from 1980, the papers showed. Seoul began to call China by the name in 1988 and forged official diplomatic ties four years later.

Seoul also feared Japan forging ties with Pyongyang, as opposition politicians attempted to link the issue with the planned execution of then leading dissident and former President Kim Dae-jung, which was never carried out. Kim, who became president in 1998 and is also the nation’s first and only Nobel Peace Prize winner, was abducted from a Tokyo hotel and sentenced to death for treason.

Tokyo pressed Seoul not to carry out the execution, warning it may be “forced” to expand exchanges with Pyongyang due to an escalating anti-South Korean mood at home.

“Should Kim Dae-jung receive capital punishment, the Japanese public will pressure the government to increase exchanges with North Korea,” then-prime minister of Japan Zenko Suzuki had told Seoul officials.

The then military-backed administration of South Korea was facing similar pressure from Washington, documents showed.

U.S. lawmakers had sought to shrink down economic cooperation and trade with South Korea should it carry out the execution, and viewed providing Kim with a shelter should he be convicted.

Kim was sentenced to death for allegedly fomenting a pro-democracy uprising in a southern South Korean city.

But his sentence was commuted to life in prison due to escalating international criticism and demands on Seoul not to carry out the execution. In 1982, Kim was pardoned and allowed to seek exile in the U.S.

Other information, among the 1,400 volumes, or 180,000 pages, of decades-old diplomatic documents unveiled Monday, included an early forecast by Seoul and Washington over North Korea’s nuclear test, and South Korea’s accurate evaluation of North Korean leader Kim Jong-il’s personality despite the limited information it had 30 years ago.

Kim had been viewed as “stubborn and aggressive” by Seoul shortly after he was named the heir apparent by his father Kim Il-sung.

Incumbent Kim Jong-il eventually took office in 1994 after the death of his father, a father-to-son succession that is expected to be repeated by his son Kim Jong-un within the next few years.

South Korea annually releases the once-confidential diplomatic dossiers under laws that took effect in 1994. Only information closely related to national security or sensitive diplomatic matters are exempt from the disclosure.

By Shin Hae-in (hayney@heraldcorp.com)