導火線 (どうかせん, doukasen) Japanese meaning: fuse | KotomoraWhen they lit the fuse, it exploded immediately.
That incident became the fuse that ignited the war.
Usage patterns
導火線に火をつけるto light the fuse
He lit the fuse and immediately ran away.
〈事〉が導火線となるfor something to become the trigger (of a larger event)
A small clash became the trigger for a long war.
導火線が短いto have a short fuse (quick to anger)
He has a short fuse, so he gets angry right away.
