They've both become more adversarial. China has been using economic blackmail to advance political goals for a long time (e.g. wrt Japan and Taiwan and SEA). They also continue to expand military based in the SCS that don't belong there, hold exercises to simulate blockades outside of China. Etc.
Just a nitpick, but it is the reverse, the United States has become more adversarial. China isn't kidnapping heads of state.