Although military-to-military relations between China and the U.S. appear to be back on track, they've been frosty for almost two years after a U.S. arms deal with Taiwan, which Beijing considers part of China.
But there is one realm where military cooperation has endured without hiccup for half a century
No, not the J-20
It's another kind of stealth fighter.
"This is the last military pigeon unit left in all of the People’s Liberation Army,” said Major Li.