Answer: casus

AnswerCrossword Clue
CASUS

".. belli" (justification for war)

CASUS

.. belli (act of war)

CASUS

... belli.

CASUS
... belli (event leading to war): Lat.
CASUS
... belli (event which leads to war): Lat.
CASUSEvent: Lat.
CASUS... belli
CASUS... belli (war starter)
CASUS..... belli (cause of war)
CASUS... belli (war-provoking act)
CASUS... belli (cause of war)