The most common and most likely answer to this crossword clue is the 8 letter word ISRAELIS
I've seen this crossword clue in The Guardian
I
S
R
A
E
L
I
S
More clues leading to the result ISRAELIS
- Former prime minister dismissing leader and southern Asians
- Is serial broadcast for Middle-Easterners?
- Countrymen capturing king from the east in section of major river
- King held up by goddess for nationals
- Conservative PM’s beginning to expel foreign nationals
- People from East of Thames stopped nonsense writer put about
- Middle Easterners’ tragic king held back by Egyptian deity
- Fundamentalists embracing real change for middle easterners
Buddy explains!

The straight part
We know that "nationals" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case nationals = israelis.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.