Probably the most disturbing photo to emerge from the anti-Japanese protests in China shows a group of men and women standing in front of an Audi dealership, and under a banner, which reads "Even if China becomes nothing but tombstones, we must exterminate the Japanese; even if we have to destroy our own country, we must take back the Diaoyu Islands."

Many Chinese still resent Japanese for the atrocities their ancestors committed when they occupied China during and before World War 2; the desire for revenge, as evinced in the banner, is worryingly common.

The German automaker Audi, for its part, seems to be trying to walk a line between responsible global company and staying out of other countries' politics. "It's the position of Audi to categorically distance itself from the message in that photo; and it's not Audi's place to comment on political matters," Brad Stertz, Audi of America corporate communications manager, told me by phone. "We want to distance ourself from any use of violence, as suggested in that banner."

Stertz also said that "it's my understanding that they're not Audi China employees;" whoever they are, the lack of loud domestic condemnation of their message does not bode well for the future of Sino-Japanese relations.