The idea of Muslims having one unifying leader is an established position in Islamic philosophy. The term for this leader is "Caliph" (successor). In his article, Mehdi Hasan makes a sweeping and quite preposterous rejection of an Islamic State having any "theological", "historical" or "empirical" evidence.
It appears my co-religionist has made a distinction between Caliphates of past and what he perceives as an 'Islamic State'. Is the term 'state' intrinsically secular? Does it require a parliament, a capitalist economic model and every political structure mimicking a modern nation state? Well, no. The error of making a distinction between a Caliphate and an Islamic State, is quite frankly, odd. A Caliphate and an Islamic State are synonymous terms. The only difference is the former is the given name of the state and the latter being its ideology.
When referring to Caliphates of the past it would be hugely inaccurate to disregard them as examples of states due to the lack of modern governmental trappings. States progress in tandem to the progression of technology and science. So to suggest that the state of Medina under the Prophet Muhammad and its political infrastructure cannot be used as an analogy for a modern Islamic State, is as absurd as saying that a horse and carriage cannot be considered a mode of transport since it lacks the modern features of a car.
The Caliphs appointed tax collectors, scribes, emissaries, judges, had a standing army (defeating the Byzantines with an army of 30,000 in Yarmouk) and governors. So to claim that there was no civil service or standing army is beyond me. The Rightly Guided, Ummayad, Abbasid and Ottoman Caliphates held treaties with states outside of their authority and received ambassadors from foreign powers, which demonstrates clearly, that they had all the components of a state. This is not derived from obsession or romance of an Islamic golden age. Rather, it is documented in history that Caliphates were the most advanced states in the world and were in fact pioneers of modern states. The tools mankind use to execute their actions change over generations, the actions however, never change - eating, travelling, trading, communicating, governing, warfare.
The Prophet Muhammad said:
"The children of Israel used to have their political affairs ruled by prophets. Whenever a prophet died another would succeed him. But there will be no prophet after me, instead there will be caliphs and they will number many." The companions asked, "What then do you order us?" Muhammad said, "Fulfil allegiance to them one after the other. Give them their dues. Verily, Allah will ask them about what he entrusted them with." Sahih Bukhari
The term "Caliphs" and the subsequent statement of "fulfil allegiance to them one after the other" indicates that the governing structure post-prophethood is a Caliphate. The Prophet Muhammad is commanding Muslims to fulfil their allegiance to every Caliph. This quote demonstrates that the only governing system he recognised and specified is the Caliphate. This command is not restricted to a particular generation of Muslims and will always exist, thus a Caliphate today would include all the familiar characteristics of a modern 'state'.
Supporters of secular liberalism often misquote Imam Shatibi (as Mehdi did). It seems that my fellow journalist is unaware that Shatabi also said, "In the absence of the Caliphate, a state of anarchy and lawlessness would prevail and this would usher in a great corruption and disorder". Thus, Shatibi did not mean to discard Islam as a political structure, nor did he suggest seeking these social principles by any political means, rather they could only be achieved through a Caliphate.
Finally, in the study which Mehdi alluded to in his article, John L Esposito and Dalia Mogahead concluded that "Majorities in many countries remarked that they do not want religious leaders to hold direct legislative or political power". This was based on 50,000 interviews with Muslims in more than 35 countries. To illustrate how convincing this statistic is I'd like to do some maths - 50,000 in a population of 1.6billion Muslims is 0.003125%, which carries as much weight as taking political advice from the Monster Raving Loony Party.
Unfortunately, many Muslims in the field of politics, academia and journalism have adopted a secular framework that has skewed their understanding of the relationship between politics and Islam. This is no surprise since the West invested heavily pre and post Ottoman Empire to ensure that Muslims would no longer desire Shariah law to play a pivotal role in their governance, since they were well aware that men die but ideas endure.
Due to this secular mentality that dominates and influences their approach to interpreting Islamic texts, they have divorced themselves from the orthodox teachings of Islam and have, as a result, become fringe themselves among the Muslim community.