However, there is a view that Yoshinobu had no choice [but to retreat] because at that time it was necessary to suppress military revolts in Edo as well as in Musashi Province, and because Yoshinobu became the Imperial Court's enemy, various clans were alienating themselves one after another from the Shogunate; thus, even if he was able to protect Osaka-jo Castle, a long-term battle had to be avoided in order to prevent interventions from foreign countries.
しかしこの時、江戸や武蔵国での武装一揆に抗する必要があったことや、慶喜が朝敵となったため諸大名の離反が相次ぎ、たとえ大坂城を守れても長期戦は必至で諸外国の介入を防ぐ必要があったために、仕方がなかったという意見もある。