The stages of the Islamic conquest of Al-Djazīra 18-20 hi / 639-641 AD

After the Muslims conquered Iraq and the Levant, they had to focus the efforts of the conquest process towards the Al-Djazra region, which is of great strategic importance, especially since the war necessity put Muslims before the inevitability of securing and strengthening the open territories in Iraq and the Levant, and standing in the face of the Byzantine recovery campaigns The conquest of the island separates the Byzantines from the Arab tribes loyal to them in the region of Al-Djazra, such as: Ghassan, Ayad, and Tanukh, and cuts off the way for any project of alliance between the Byzantines and the Persians against the Muslims, especially And that the eastern part of Al-Djazra was subject to the Sassanids loyal to the Persians, who did not show much resistance and quickly surrendered to the advance of the Islamic forces coming from Iraq and Mosul, and thus the process of liberating Al-Djazra was completed, a process that only took eighteen months, what are the major stages of this Al-Fateh? What is its strategic importance .