What is the origin of the idiom "cut the ground from under someone's feet" and when to use it?

The idiom "cut the ground from under someone's feet" is believed to have originated as a military tactic in which an attacking army would dig trenches around a fortified position to isolate and weaken the defenders. In modern usage, the phrase is commonly used in a figurative sense to describe situations where someone's position or advantage is suddenly taken away, leaving them without a foundation to stand on.