CAIRO — Since the group known as the Islamic State of Iraq and Syria (ISIS) declared a caliphate, much has been written about the movement — but still more remains unclear.

How seriously should we take their rise? How does ISIS define Islamic law, and how would it be implemented? There are also more basic questions about the group's origins and its finances.

Some compare its meteoric rise to the ascent of the Taliban, which ideologically and militarily might be true — but there is an essential difference: While the Taliban and most other Islamist movements function in the Westphalian state model defined by national sovereignty, ISIS rejects it, effectively making it the first post-Westphalian entity to arise since the end of colonialism. And the consequences could be dire.

The nation-state as we know it today is a result of the Westphalian peace agreements, signed in what is now Germany in 1648, which ended the Thirty Years' War. During this war, different states and principalities linked to either the Catholic or Protestant faith would support citizens in other principalities to get rid of their rulers, if those rulers adhered to the other faith. With the Westphalian peace, all states agreed that this was a bad idea, and that each state had absolute sovereignty over all people living within its boundaries, but no sovereignty beyond those boundaries. Additionally, all states were defined as equal, and war was recognized as a legitimate medium of conflict resolution between states.

The key element of the Westphalian system was not borders per se, but the idea of absolute sovereignty. The border at which one sovereignty ends and another begins is a product. If there can be no overlap of sovereignty, and all territory falls under a certain sovereignty, then a border automatically emerges. As a result, the Westphalian system has no problem with borders changing or states emerging or disappearing, as long as the sovereignties in each resulting territory are clear and absolute.

A double obsession

The Westphalian state model stood in contrast to the old empire, which in principle recognized no borders and whose sphere of influence usually would not end at a specific line, but would fade out. Influence would have a varying character, and could include semi-sovereign sub-units, which would pay tribute more or less regularly — a classical example would be the Ottoman Empire.

The real implementation of the Westphalian system has never been as clear as theory would suggest. In a sense, colonialism was a challenge to the Westphalian system as European states turned into empires. But unlike the empires of Tamerlane, Rome or Persia, the new European empires were simultaneously obsessed with expansion and with boundaries — an obsession that eventually stuck us with lots of artificial borders in Africa and the Arab world.

Since then, there were all kinds of countries and groups that wanted to change the colonial borders, or that questioned where the borders really were. As a result, new countries like South Sudan appeared, countries like Libya invaded neighbors like Chad, and territories like the Halayeb triangle remained somehow ambivalent. However, these represented no challenges to the Westphalian system as such, as none of these groups were trying to do away with borders.

But even after the end of colonialism, the Westphalian system keeps being challenged. Firstly, supra-national institutions like the European Union, the United Nations and the International Criminal Court limit the absolute sovereignty of states within their borders. Secondly, international military interventions motivated by the so-called “responsibility to protect,” such as the Kosovo and Libya interventions, claim that the international community can bear responsibility for minorities or civilians in sovereign states, especially if these minorities are threatened with genocide. Thirdly, during the Cold War, communism — at least in principle — wanted to overcome the division into state-units, but even in the communist bloc this never happened. The Westphalian system proved to be rather obstinate.

What's in a name

While all these developments were mere modifications of the Westphalian system, the Islamic State wants to eliminate the system completely. Reflected in its name change from the "Islamic State of Iraq and Syria" to simply "Islamic State," the movement does not aim to establish governance within specific borders, but rejects borders as such. In a video produced by the group, a young fighter called Abu Safiyya declared that “there are no nationalities. We are all Muslims, there is only one country.” He goes on to refer to all national flags as “kafir” (infidel).

Therefore, in its conception of the state, the ISIS has more in common with the empire of Alexander the Great than with the Taliban in Afghanistan. This might be one aspect which makes ISIS attractive for radical Muslims from around the world. They do not propose a particular national vision, but rather an internationalist utopia.

It would, however, be a mistake to assume that ISIS is archaic or medieval. The way the movement quickly spread, the way it was able to make use of its opponents’ weaknesses, the way it uses social media as a tool to advertise and recruit, but also as a tool of strategic warfare, demonstrates that it is clearly adapted to and rooted in the modern world: more Mad Max than Saladin.

Forced to adapt its strategies to spread its governance entity in a world organized by the Westphalian system, ISIS" ambition is a caliphate that is clearly not pre-Westphalian, but post-Westphalian.

The rejection of the modern state as an innovation incompatible with Islamic doctrine is based on the idea of the ummah. In a modern context, ummah would mean nation, or community, but traditionally it refers to the collective of all believers as they were ruled by one governance entity during the time of the Prophet — and then to a greater or lesser degree under the subsequent caliphs.

But with every country that ISIS attacks, it gains new enemies and becomes more vulnerable. Their ability to expand will basically be determined by three factors: the number of fighters who join from around the world, the level of local support and the degree to which the West is ready to get involved.

Either way, a quick further expansion would likely result in overstretch, and the caliphate could collapse as quickly as it appeared.