Rasulullah ﷺ said:
تكون النبوة فيكم ما شاء الله أن تكون ، ثم يرفعها الله إذا شاء أن يرفعها ، ثم تكون خلافة على منهاج النبوة ، فتكون ما شاء الله أن تكون ، ثم يرفعها الله إذا شاء أن يرفعها ، ثم تكون ملكا عاضا ، فيكون ما شاء الله أن تكون ، ثم يرفعها الله إذا شاء أن يرفعها ، ثم يكون ملكا جبريا ، فتكون ما شاء الله أن تكون ، ثم يرفعها إذا شاء أن يرفعها ، ثم تكون خلافة على منهاج النبوة ، ثم سكت
From this Sahih hadith we are informed that between the original khilafah upon the prophetic minhaj and the eventual return to that minhaj, there will not be any ruling system other than varying degrees of error and injustice, oppression and coercion. We also know that khilafah did not end in 1924, but 30 years after the death of the Prophet ﷺ, immediately after which we have known only imperfect governing methodologies. Rasulullah ﷺ said:
الخلافة بعدي في أمتي ثلاثون سنة ثم ملك بعد ذلك
It matters very little what title these systems called themselves, our Prophet ﷺhas identified them honestly.
Furthermore, Rasulullah ﷺ did not declare the governments that would follow Khilafah to be invalid, indeed, he ordered us to obey the rulers which would come after Khilafah, and to fight them only if they committed open kufr. In whatever is less than Kufr, we are required, not to overthrow the government and establish a new one which we call Khilafah, but to do our best to advise the rulers and influence state policy in ways that bring it closer to the Truth.
The point here is that there is no actual obligatory governmental model, there is only the struggle for adhering as much as possible to the prophetic minhaj, and this has less to do with structure than with the values and principles used to guide policymaking.
Certainly, there were great structural differences between the administrations of the Khulafah Rashideen, including the selection process, and several developments in the institutional mechanisms of the 4 governments. “Minhaj nubuwwa” clearly does not refer to governmental structure or form, but rather it refers to the administration’s nature and sincere commitment to the Deen and the best interests of the Muslims.
Changing the method of selecting the ruler to a system of inheriting power from fathers to sons, yes, has to do with governmental form, but more importantly, it reflects a departure from the principle of sincere interest in choosing the best qualified leader, and this is the key point which represents the divergence from the prophetic minhaj. However, this divergence does not invalidate the government.
Establishing a government which we call Khilafah is not an obligation, We had governments of kings and oppressors for the last 1400 years, and until 1924 we called all of this Khilafah.
We do not need a return of Khilafah, we need a return of the minhaj nubuwwa, and that can potentially exist to varying degrees in any government; just as it existed in varying degrees since the death of Amir-ul-Mu’mineen Ali bin Abi Talib, in all of the subsequent regimes that our Prophet ﷺ called kings and oppressors.
Establishing any form of government which we call Khilafah, and even which seems to adhere to the structural elements of the first four Khulafah does not indicate at all that it is on the minhaj nubuwwa, and there is no reason to regard it as better than any other governmental system.
Implementation of Shari’ah, promoting Islamic practice and the best interests of the Muslims, undoubtedly can be undertaken by any governmental system at all which is bound by an Islamic constitution. Why not?
There is no doubt that a time will come when government according to the minhaj Nubuwwa will return, but when Rasulullah used the word khilafah he was not referring to the name of a system, but simply to the succession of authority.
As I said, we had what Rasulullah called tyrants and kings ever since the death of ‘Ali, although it was under a system calling itself Khilafah. Obviously, authority will return to the minhaj nubuwwa , but calling a system Khilafah does not make it so.
The point is not the name of the system, but the manner in which it governs