Yoshitsune's precipitous attack at Dannoura lead Emperor Antoku and TAIRA no Tokiko to commit suicide and the disappearance of Hoken (treasured sword), which could have been a good instrument to use for negotiating with the Imperial court, and as a result, destroyed the post-war initiative that Yoritomo had conceived.
また義経の性急な壇ノ浦での攻撃で、安徳天皇や平時子を自殺に追い込み、朝廷との取引材料と成り得た宝剣を紛失した事は頼朝の戦後構想を破壊するものであった。