Obviously, I can see how you got Kenya for "key not p-plicble" = anagram of key + n/a. However, whilst I can also get CHINA for this clue, no other countries apart from KENYA gives a solution to the "yankee" clue!
As I see all the answers that you have already it is getting more confusing!
A key not applicable, could "possibly" be TONGA
Backwards it is
A G(key in music) "not" and applicable means 'stick it together"
= agnot = Tonga backwards