姑息养奸的英文：
[Literal Meaning]
yield to/foment/bad people or bad things
to foment evil by tolerating bad people or bad things

[解释]
无原则地宽容，只会助长坏人作恶。

[Explanation]
To tolerate evil is to abet it.

[例子]
如果你不惩罚那些逃兵就等于是姑息养奸，早晚有一天他们会背叛你的。

[Example]
If you don't punish those deserters, it is like to nurse a viper in your bosom and they will betray you sooner or later.

cherish [ nourish ] a viper in one's bosom
厚待忘恩负义的人,姑息养奸

Indulge the evil-doers;purposely tolerate bad things
姑息养奸

We mustn't wrong innocent people and palliative enemies.
我们不能冤枉好人也不能姑息养奸。