Germans in WW II (not in WW I), Japanese in WW II (in both cases, early on, we got better as years went by ** -- we may not always have that time...), Chinese in Korea (not North Koreans), VC Main Force in Viet Nam 1962-68 (not PAVN / NVA).

While there's no question we were better trained than the opponents in Grenada, Panama or Iraq, we had some embarrassing and, more importantly, deadly induced problems in all three. Same is true of Somalia -- where a raggedy Militia 'Colonel' said of our operations after the very bad day in Mogadishu; "They did the same thing over and over. Tactically you never do the same thing twice" (or words to that effect).


* There were strategic failures by us in most as well but that's not a training or even a military issue, it's a political issue.

** The recurring complaint of WW II combat arms folks was that their stateside training was inadequate