It is unfortunate that you see today in many Muslim countries branches of (international) banks that deal in usury and interest. This is due to globalization, a

It is unfortunate that you see today in many Muslim countries branches of (international) banks that deal in usury and interest. This is due to globalization, and the willingness of the rulers to allow anything the West wants. There are Islamic alternatives to many of traditional interest based transactions. Unfortunately there is still quite some debate around them, as there does not seem to be any sense of urgency or proper funding being provided to push for that, given that many people are lax, and accept the status quo. What there is _no_ debate about, is that dealing in usury (e.g. savings accounts, or taking an interest bearing loan) is prohibited Islamically. Certain exemptions are made to people that have this as their only alternative, other than being thrown out on the street if they can't pay their rent for instance. However, this is only reserved for dire situations, and some people take this too far, and think that they can be exempted, whereas they cannot. It is the responsibility of the community to provide for the poor first and foremost. I would need to look up to see where this shift started to happen, but I would not be surprised if it started to take place at, or around WWI (that's when a lot of other problems started to happen in the region). If that turns out to be the case, then yes, it is quite sustainable that it lasted for over 1250 years.