hair trigger

あけましておめでとうございます。元旦生まれなので年明けとともに年齢が一つ増えました。今年が７０代で迎える最後の年です。会社勤めもおそらく今年で最後でしょう。仕事は明日からですが、今日から今年のブログを始めます。
さて、村上龍の小説の "In the Miso Soup" を読んでいます。

Yakuza hoods are the classic example, but people like Noriko get this way sometimes. Drunk or sober, she always had a hair trigger, and you could never tell how she was going to react to anything you said. With no warning whatsoever, even when you've meant no offense, people like her will suddenly decide you're disrespecting them.

"hair trigger" は髪の毛でもトリガーになると理解できるので、普通の言葉で言うと敏感の意味だと推測します。辞書で確認します。

・Collins Dictionary: If you describe something as hair-trigger, you mean that it is likely to change very violently and suddenly.: His boozing, arrogance, and hair-trigger temper have often led him into ugly nightclub brawls.; A hair-trigger situation has been created which could lead to an outbreak of war at any time.
・Cambridge English Dictionary: the characteristic of becoming very angry very easily: Those bombers were the very stuff of hair-trigger response.

超大国のトップが "hair trigger" だと恐ろしいことになりますね。.