The Khalifah is the leader of the army and he is the one who appoints the Chief of Staff and an Amir to every brigade, and a commander to every division. In regards to the other posts in the army they are appointed by the commanders of the brigades. In regards to appointing a person to the staff, it has to be according to his military culture and he is appointed by the Chief of Staff. .

This is because the Khalifah is the general leadership of all the Muslims in the world, for establishing the Shariah rules and conveying the message to the world. The way of conveying the message to the world is through Jihad. Therefore, the Khalifah should take charge of the Jihad because the Khilafah contract has been convened to him alone, so it is not allowed for any other person to carry it out other than himself. Thus the Khalifah takes responsibility for Jihad himself. It is not allowed for anyone other than him to undertake it, although every Muslim carries out Jihad. Hence carrying out Jihad is one matter and holding the responsibility for it is another. Jihad is a duty upon every Muslim, but holding the responsibility for the Jihad is only for the Khalifah. .

However the Khalifah may appoint another person on his behalf to carry out this duty, which is allowed under his own observation and supervision but it is not allowed for it to be done in an independent way without his observation and supervision. This type of delegation is not the same as the work of an assistant to the Khalifah. Reporting to the Khalifah in this context means that the one who carries out Jihad on his behalf should be under his supervision. Leadership of the army with this restriction i.e. under the Khalifah’s observation and supervision, is allowed to be given to whomever he wishes. But to take charge of the army without his observation and supervision leaving the Khalifah only as a figurehead, is not allowed. This is because the Khilafah contract has been convened upon him, so he has to take the responsibility for the matters of Jihad. Therefore, what is usually said in the non-Islamic systems is that the head of State is the supreme leader of the army, meaning he is a formal leader only, while another leader runs the army independently, an opinion which is considered invalid in the view of Islam. It is a matter which is not approved by the Shariah, rather, shara obliges the Khalifah to be the actual leader of the army. However for other types of leadership issues like the administrative and technical matters, the Khalifah is allowed to appoint someone on his behalf to carry them out independently, and it is necessary that they be under his actual observation like the leadership. .

Also the Messenger (PBUH) used to undertake the leadership of the army himself, undertake the leadership of the battles and he also appointed leaders of the divisions of the army which went out for fighting without him, namely the expeditions. For every expedition he used to appoint a commander and in some cases he used to take the precaution of naming who should succeed the commander in case he was killed as happened in the expedition of Mu’ta. Al Bukhari narrated on the authority of Abdullah b. ‘Umar who said: .

“The Messenger of Allah (PBUH) appointed Zayd bin Harith as an Amir in the battle of Mu’ta. The Messenger of Allah (PBUH) said: “If Zayd is killed, then it will be Ja’far (as the Amir) and if Ja’far is killed then it will be Abdullah b. Ruwahah (as the Amir ).’” So the Khalifah is the one who appoints the leaders of the armies, its commanders, ties for them the flags and appoints the leaders of the divisions. .

So the army which was sent to Syria like the Army of Mu’ta and the army of Usama, was one brigade because the evidence for this is that the Prophet (PBUH) had tied the flag to Usama. Also the expeditions which fought in the Arabian Peninsula and would return back to Madinah such as the expedition of Sa’d bin Waqqas which he sent towards Makkah were in the form of divisions. This indicates that the Amirs of the brigades and the commanders of the divisions are appointed by the Khalifah. However, other than the amirs of the army and brigades of the divisions, it was not proved that the Messenger (PBUH) appointed them. This means he left their appointment in the expedition to their leaders. In regards to the Chief of Staff who is responsible for the technical matters, he is like the army leader in terms of being appointed by the Khalifah and he can be made independent and carry out his duties without being directly supervised by the Khalifah, although he has to be under his command.