When America lost in Vietnam it was at least an honorable defeat: both the USSR and the PRC invested vast quantities of materiel and military advisors into the war. For decades. It was fought with stuff that was designed for WW3.
There's no "worthiness", no "honor" in war. There's just dumb young men being sent to kill, rape, and die by evil old men.
The only exception is if you're fighting purely in defense of your country. But that's not what any of these so called "honorable, worthy" opponents were doing.