A direct war (even conventional warfare, which can quickly escalate) between nuclear-armed states could be the demise of mankind. Please remember that.
It wouldn't be a direct war in the sense everyone is thinking. The US has several strategies published regarding war with China with the most likely strategy being one of containment, not outright invasion. I'm saying that the open markets and globalization that has happened over the last several decades (And is now being reversed) is the reason we have had relative peace (No war between larger powers) since WWII