The US has banned all American companies and banks from dealing with Syria.

No American is now allowed to hold an account with the Commercial Bank of Syria, making life difficult for the many US residents in Damascus.

But more importantly, it adds another hurdle for American companies to do business in Syria. Now, all earnings will have to be shipped out of the country in cash - a practically impossible situation.

And it will undoubtedly push Syria back towards its tried and tested policy of economic isolation, at a time when Syrian reformers are trying to open the country up to foreign investment.