(n)cutting in two with a single stroke; taking decisive (drastic) measure; cutting the (Gordian) knot
もう少しやさしく意見してあげたらどうなの。一刀両断のもと切り捨てられた彼の立場も考えてよ。 Why don't you try expressing your opinion a little more gently? Think about how he feels getting told flatly that he's being cut loose.
Japanese Dictionary
