There are many contrivances mentioned in the scriptures. Of them persons acquainted with the past history have mentioned battle as the most sinful.
माया हि बहवः सन्ति शास्त्रमाश्रित्य चिन्तिताः। तेषां युद्धं तु पापिष्ठं वेदयन्ति पुराविदः॥