From the New York Times Op-ed article by Mingxin Pei:
The state of the U.S.-China relationship exhibits classic symptoms of a bipolar disorder — sudden and dramatic swings between euphoria and depression. Barely three months ago, when President Obama was feted in Beijing, it was euphoria. At the moment, when Beijing hurls insults at Washington almost daily, it is decidedly depression.
The rapid downturn in a relationship that was, until recently, marked by cordiality and tranquility has led many to worry about another extreme: a qualitative deterioration and eventually a full-fledged rivalry.
Such fears are overblown, in the same way that recent talks of a close-knit U.S.-China strategic partnership (a.k.a. G-2) were premature and naïve.
In many ways, the sudden worsening of ties between Beijing and Washington really means that U.S.-China relations are returning to “normalcy.” Because of the deep and unbridgeable differences between the two countries in terms of their political values, conceptions of international order and geopolitical interests, constant frictions, even minor conflicts, should be the rule. Chumminess and absence of tensions, as displayed during Mr. Obama’s first year in office, are actually the exception.