Complex sentence: During the late 1980s and early 1990s most of these "Communist" regimes collapsed and adopted capitalistic economic policies, even though some remained nominally communist, like the People's Republic of China.
Split into simpler sentences: During the late 1980s and early 1990s, most of these "Communist" regimes fell from power, and were replaced by governments which adopted capitalistic economic policies. In some cases, nominally Communist governments themselves adopted capitalistic policies, such as in the People's Republic of China.