incremental morale degradation

A step by step reduction in the psychological condition of an individual or group.

Despite being fully capable of success, Joe went through incremental morale degradation over the period of several years and no longer wanted to succeed.

Incremental morale degradation struck the heart of the soccer team. What started as confidence and hope for an easy win turned into a psychological train wreck.

They used incremental morale degradation techniques against the troops. Surrender seemed like the only option.