Right, but China is untrustworthy in a standard international wheeling and dealing sense, while Russia and the US are both direct, existential threats to the EU and its constituent nations.
Yes - they'd be best off avoiding entanglements with all three, but their very survival might depend on allying with China against an overtly hostile Russia and US.
I guess, in the same sense that ones relationship with two hungry-looking men with their hands wrapped around suspicious bulges in their pockets, advancing on you from opposite ends of a dark alley and already arguing over who gets to keep your watch might be considered "volatile."