The Muslims are obliged to live in one State, and be ruled by one Khalifah. It is forbidden for the Muslims in the world to have more than one State and more than one Khalifah. .

It is also necessary that the ruling system in the Khilafah State be a system of unity, and it is forbidden for it to be a federal system. .

This is due to what Muslim narrated on the authority of Abdullah b. Amru b. al- Aas who reported that he heard the Messenger of Allah (P.B.U.H) say: .

"Whoever pledged allegiance to an Imam giving him the clasp of his hand and the fruit of his heart, he should obey him as much as he can, and if another comes to dispute with him, you must strike the neck of the latter". .

It has also been narrated by Muslim that Afrajah said: “I heard the Messenger of Allah (P.B.U.H) say: .

"Whoever comes to you while your affair has been united over one man, intending to divide your power or dissolve your unity, kill him".” [Muslim, Sahih, #1844] .

It has also been reported by Muslim from Abu Said Al Khudri that the Messenger of Allah (P.B.U.H) said: .

"If the Oath of Allegiance (bayah) has been taken for two Khalifahs, kill the latter of them." [Muslim, Sahih, #1853] .

Muslim also reported that Abu Hazim said, “I accompanied Abu Huraira for five years and heard him talking about the Prophet’s (P.B.U.H) saying: .

"The children of Israel have been governed by Prophet; whenever a Prophet died another Prophet succeeded him; but there will be no Prophet after me. There will soon be Khulafaa and they will number many; they asked: What then do you order us? .

He (P.B.U.H) said: Fulfil allegiance to them one after the other, and give them their dues; for verily Allah will ask them about what he entrusted them with".”[Bukhari, Sahih, #3455] ..

The first hadith demonstrates that if the Imamah (Khilafah) has been given to someone he should be obeyed, and if another man comes to dispute his authority, he should be fought and killed if he did not renounce the dispute. .

The second hadith demonstrates that when the Muslims are united under the leadership of one Amir, and a person comes along with the intent to divide their power and dissolve their unity, his killing becomes compulsory. The two hadiths clearly indicate prohibition of dismembering the State, the strong warning against its division, and preventing any breakaway attempt even if it means raising the sword (force). .

The third hadith indicates that in the case of the absence of a Khalifah, due to death, removal or resignation, and the contracting of the bayah to two Khulafaa, the latter of them should be killed. This means the Khalifah is he who was given the first bayah, whilst the one that who was given the bayah after the first must be killed if he does not withdraw himself from Khilafah post. If the bayah was taken to more than two, then all those, except the first person given the bayah must be fought and killed unless they withdrew from the bayah. This clearly demonstrates that the dismembering of the State is forbidden, which means that turning it into small Statelets is forbidden; it must remain one single State. .

The fourth hadith indicates that the Khulafaa would number many after the Messenger of Allah (P.B.U.H) and that the Sahabah asked him about what he ordered them to do when the Khulafaa numbered many, and he replied that they should fulfil their allegiance to the Khulafaa one after the other, starting by the first one they gave their bayah to, for he would be the legitimate one and he alone should be obeyed. As for the others, they are not to be obeyed for their bayah is void and null and unlawful, for it is forbidden for another Khalifah to be given a bayah while there exists a Khalifah already in office. This hadith also indicates that obedience to a single Khalifah is obligatory. Therefore it is forbidden for the Muslims to have more than one Khalifah and more than one single State.