Complex sentence: Initially, as a terrorist organization, the PLO primarily attacked Jewish civilians in Israel in the 1970s and early 1980s, regarded as terroristic activities by Israel and regarded as a war of liberation by the PLO.
Split into simpler sentences: Initially, as a terrorist organization, the PLO primarily attacked Jewish civilians in Israel in the 1970s and early 1980s. Regarded as terroristic activities by Israel and regarded as a war of liberation by the PLO.