Explanation: https://en.wikipedia.org/wiki/Gordian_Knot
The cutting of the Gordian Knot is an Ancient Greek legend associated with Alexander the Great in Gordium in Phrygia, regarding a complex knot that tied an oxcart. Reputedly, whoever could untie it would be destined to rule all of Asia. In 333 BCE, Alexander was challenged to untie the knot. Instead of untangling it laboriously as expected, he dramatically cut through it with his sword. This is used as a metaphor for using brute force to solve a seemingly-intractable problem.