Complex sentence: Outside of the inner core of the PDF Noriega did not have strong support similar to the civilian population and the majority of the PDF surrendered quickly when the United States invaded Panama and overthrew Noriega in 1989.
Split into simpler sentences: Outside of the inner core of the PDF Noriega did not have strong support similar to the civilian population. The majority of the PDF surrendered quickly when the United States invaded Panama and overthrew Noriega in 1989.