His father's side of the family is from Kosovo. As a child, Djokovic was terrified by the NATO warplanes that bombed Belgrade in 1999 to stop Serbian armed offensives against ethnic Albanians in Kosovo. ("When I hear a big noise even now, I get a little traumatized.")
Critics seized on Djokovic's comments to the rally as evidence of the nastiness lurking beneath even the acceptable face of Serbian patriotism.
"I don't want to expose my opinion on that too much because they will use it against me," he said warily, when asked about the episode in a subsequent interview.
For the moment, he's happy to keep on expressing how proud he is to be Serbian without getting drawn into uncomfortable specifics. And his countrymen are happy to project onto him their aspirations for a New Serbia.
With his loss at the French Open, the next goal for Djokovic, who says he's feeling particularly fit nowadays in part thanks to a gluten-free diet, is to conquer Wimbledon, which begins this month.
The last time someone from the Balkans won the men's title was 10 years ago. That player was Goran Ivanisevic, a Croat.
Now Djokovic and Serbia want their moment in the sun, as little by little they seek to banish the shadows that hang over their past.
Chu was recently on assignment in Belgrade.