Retreat for progress is one of the art of war used by many famous soldiers in ancient times.

Dilemma, dilemma.

The story of Yang Xiu and chicken ribs (chicken ribs are tasteless, but the meat is discarded) means neither advancing nor retreating.

Advance can attack, retreat can defend.

Fan Zhongyan: if you advance, you will be worried, and if you retreat, you will be worried.