楔くさびを打うち込こむ

expression, godan verb (-mu)

drive a wedge into; wedge apart

Literal and figurative use: physically inserting a wedge to split something, or metaphorically creating a division or foothold within a group, defense, or relationship.

• 敵てきの戦せん線せんに楔くさびを打うち込こむ作さく戦せんを立たてた。

  They devised a plan to drive a wedge into the enemy lines.

• 彼かれの発はつ言げんが二人ふたりの友ゆう情じょうに楔くさびを打うち込こんだ。

  His remark drove a wedge between the two friends.