Among the many important international meetings earlier this month — the Asia Pacific Economic Cooperation (APEC) forum and the sit-downs among assembled heads of state on the sidelines, and the Group of 20 meeting in Australia — one of the most vital, surpassing even the long-anticipated encounter between Prime Minister Shinzo Abe and Chinese President Xi Jinping, was the summit between Xi and U.S. President Barack Obama.

A relationship that U.S. Secretary of State John Kerry recently called "the most consequential in the world today, period" has been deteriorating, battered by a series of incidents and mounting distrust and suspicion on both sides. This slide in relations is a vivid counterpoint to the high hopes created by the "shirt sleeves summit" between Obama and Xi in Sunnylands, California, a little over a year ago. Then, the two men agreed to establish a "new type of major country relations" that would channel and dissipate tensions created by China's rise and Beijing's claim to greater power and influence within East Asia.

Since then, relations have eroded, with Washington charging Beijing with hacking civilian and military computer systems and the theft of terabytes of information for economic espionage. Equally alarming has been Beijing's assertiveness in the East and South China Seas — the hallmark of a rising power — and its threat, real and potential, to freedom of navigation. Finally, the United States, along with other developed nations, worry about China's readiness to challenge established rules, norms and institutions of the global order. Beijing seems set on undermining existing mechanisms of global governance and either rewriting their operating principles or setting new ones.