The most common and most likely answer to this crossword clue is the 10 letter word REARMAMENT
I've seen this crossword clue in The Daily Telegraph
R
E
A
R
M
A
M
E
N
T
More clues leading to the result REARMAMENT
- Look after guys in judo area preparing to fight again
- Mere mantra being spouted – will that encourage war again?
- Back with soldiers in dull initiative to prepare for war again?
- Soldiers in back position with dull uniform finish getting new weapons
- Back Massachusetts workers to gain tons of new equipment
- Guys in back get tangled up in treaty violation
Buddy explains!

The straight part
We know that "initiative to prepare for war again" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case initiative to prepare for war again = rearmament.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.
What does REARMAMENT mean?
REARMAMENT noun- The process of rearming.