Everett Wheeler argues that "the Sassanids, administratively more centralized than the Parthians, formally organized defense of their territory, although they lacked a standing army until Khosrau I".
Everett Wheeler berpendapat bahwa "Sassaniyah, secara administratif lebih terpusat daripada Parthia, secara formal mengatur pertahanan wilayah mereka, meskipun mereka kekurangan pasukan tempur sampai masa Khosrau I".