Complex sentence: In the 1970s, Kim Il-sung decided to begin work on the development of a nuclear weapons capability, having concluded that the development of a nuclear deterrent was the only means of ensuring the North Korean regime's survival.
Split into simpler sentences: In the 1970s, Kim Il-sung decided to begin work on the development of a nuclear weapons capability. He concluded that the development of a nuclear deterrent was the only means of ensuring the North Korean regime's survival.