The best explanation for President Richard Nixon's trip to China and the opening of relations is:
To try to sow division between the Soviet Union and China.
Nixon's visit in 1972 was strategic, aimed at leveraging the existing tensions between China and the Soviet Union to benefit U.S. foreign policy interests during the Cold War. This realignment was part of a broader strategy of détente, but the primary focus was on creating a rift between the two communist superpowers.