What does the cryptic crossword clue "WW1 soldier at end of leave gets this order wrong (4,2,5)" mean?

The definition is "wrong". The wordplay uses a double definition. Double definition The answer is BACK TO FRONT.

WW1 soldier at end of leave gets this order wrong (4,2,5)

Times Cryptic #28615 | 3 Down | 2023-05-29 flower