This saber rattling is probably more directed at Taiwan, but Xi may also be flexing the "nationalism" muscle to bolster his position in his heated relations with the US.
https://www.msn.com/en-us/news/world/xi-jinping-tells-chinese-army-to-be-ready-for-battle/ar-BBRQL4n?OCID=ems.display.welcomeexperience (https://www.msn.com/en-us/news/world/xi-jinping-tells-chinese-army-to-be-ready-for-battle/ar-BBRQL4n?OCID=ems.display.welcomeexperience)