What does the cryptic crossword clue "National leader upset at foe's death (4,2,5)" mean?

The wordplay uses an anagram. anagram of AT + FOE'S + DEATH = HEADOFSTATE The answer is HEADOFSTATE.

National leader upset at foe's death (4,2,5)

Daily Mail Cryptic #17290 | 19 Across | 2024-02-09 flower