The atrocities of the US are not strictly in the past, though our biggest and boldest known atrocities are. That being said I would say that we have benefitted from the atrocities of the past; the land I live on was once populated by people that my government participated in the genocide of. More importantly, I said nothing about people. Does the average Chinese citizen benefit directly from the atrocities of the Chinese government? Is the answer to that question even relevant to whether your prior condemnation of China was fair? Why shift to examining citizens in the case of the US but not in the case of China?