My top 5 guess would be:
1. USA (hits: tech, production) (misses: low active duty, politicians)
2. Russia (hits: production, tech, sheer will power) (misses: economy, location)
3. China (hits: production, manpower) (misses: naval, air force, food resources)
4. Israel (hits: tech, training, mandatory service) (misses: productions, resources)
5. North Korea (hits: active duty size, will power) (misses: economy, air force)
FYI: Vietnam was part of the French indo-China empire and we stepped in to stop the spread of communisum. We were fighting not only North Vietnam but a silent China as well. And politicians where afraid esculated military control would bring on WWIII so they capped military ability to fight the war.
http://en.wikipedia.org/wiki/Battle_of_Dien_Bien_Phu