One of the reasons why ISIS has been attractive to some foreign volunteers is because of its claim that it’s an “Islamic State”, or the only “Islamic State” in the World which is strictly run in accordance to Koranic laws. Or so the group claims.
Between April and May this year, Pew Research Center carried out a survey involving 10,194 respondents in 10 Muslim countries. In each country, local citizens were asked: “how much should the Quran influence our country’s laws?”
“In Pakistan, the Palestinian territories, Jordan, Malaysia and Senegal, roughly half or more of the full population says that laws in their country should strictly follow the teachings of the Quran. By contrast, in Burkina Faso, Turkey, Lebanon and Indonesia, less than a quarter agree. And in many of these countries where non-Muslims make up a significant portion of the population, there are strong disagreements between major religious groups on this issue.” (I emboldened parts of the paragraph).
You can see the survey in more details here
One country which is glaringly missing in this survey is the Islamic Republic of Iran. For example, if laws passed by the parliament are not in accordance to the constitution and Sharia laws, they can be referred back to the parliament for further revision and amendments, or even rejected by the Guardian Council.