stab in the back 放冷箭

中国有句古话叫“明枪易躲暗箭难防”，你知道这句话用英文怎么说吗？

放冷箭，中文俗语，“冷箭”同“暗箭”，表示“an arrow shot from hiding”，放冷箭指“乘人不备，放箭伤人（to shoot at someone from a position where you cannot be seen）”，比喻“暗中伤人”，英文可以翻译为“stab in the back”，或“resort to underhand means”。

例句：

明枪易躲，暗箭难防。

It is easy to dodge a spear in the open, but hard to guard against an arrow shot from hiding.

哈曼声称，嫉妒的同事暗箭伤人，她是受害者。

Harman claimed she was the victim of backstabbing by jealous colleagues.

他们说了会支持我，但是事实上，他们却在背后放冷箭！

They told me they would back me up. But as a matter of fact, they stabbed me in the back.