Is the US-China relationship the most consequential relationship for America in the world?

The invitation from Brookings' debate organizers asked: "Is the U.S.-China relationship the most consequential bilateral relationship for the United States in the world?" My answer is: yes. If not China, who? China is: An existential threat. In 2024, there are two--and only two--nations in the world that have nuclear arsenals that can literally erase the United States from the map. China is, therefore, one of only two nations that poses a genuinely existential threat--that is, one that threatens our existence--to the United States. It is one of only two nations with which the United States is required to survive in a relationship cold warriors described as MAD (mutually assured destruction)--a condition that creates an overriding shared imperative for both countries' leaders to avoid a nuclear war in which their countries would be the first victims.