The most common and most likely answer to this crossword clue is the 7 letter word ERITREA
I've seen this crossword clue in The Times
E
R
I
T
R
E
A
More clues leading to the result ERITREA
- A royal flag from the east African land
- Nation's technology about to feature in Time
- English liturgy adopted at first around Republican state
- . Country‘s flag raised with backing of American head of state
- Baedeker: it really captures Red Sea land
- Country’s merit realised to some extent
- Introduction of religious rite performed in each country
- Time to take in strange rite by the Red Sea
- Corrupt secretariat cast out of country
- A sovereign wants flag raised in African country
Buddy explains!

The straight part
We know that "Nation's" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case nation's = eritrea.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.