"Crossing the river and demolishing the bridge" literally means dismantling the bridge after crossing the river. It is a metaphor for kicking away those who once helped you once you have achieved your goal, and it falls under the category of ungrateful behavior. This idiom originates from a record in the History of Yuan and carries a strongly derogatory connotation. It is often used to condemn those who forget righteousness in the pursuit of profit and betray trust. In scenarios such as interpersonal relationships, workplace cooperation, and political struggles, if one party turns their back on those who helped them after gaining assistance, the idiom "crossing the river and demolishing the bridge" can be used to describe it. It reveals the selfish and cold-hearted side of human nature, reminding people to be grateful, while also warning people to be wary of petty individuals who are strongly utilitarian and prone to crossing the river and demolishing the bridge. It is similar in meaning to "killing the donkey after it has done its work at the mill" and "cooking the hound once the rabbit is caught," but "crossing the river and demolishing the bridge" places greater emphasis on actively destroying the very path through which one was helped.
📝 Example
He kicked Old Zhang to the curb as soon as he had made use of his technical skills, pushing him out of the company. (A metaphor for abandoning those who helped you once you have achieved your goal.)
Many founding emperors in history burned their bridges and slaughtered their meritorious officials, which is disheartening. (A metaphor for persecuting former allies after achieving success.)