The promise of web service interoperability is achievable if certain technical and non-technical issues are dealt with properly. As the world gets smaller and smaller thanks to our growing global economy the need for security is increasing. The use of security is vital in the transferring of data from one server to another. As new security standards and protocols are created, the environments for web service hosts and clients must be in sync so that they can communicate on the same standard and protocols. For example, if a new protocol x can only be implemented on computers built after 2010 then all computers built prior to 2010 will not be able to connect to any web service hosts that only use this protocol in its security policy. If both the host and client of a web service cannot communicate using a set of common standards and protocols then web services are not available to these clients thus breaking the promise of interoperability.
 
Another limiting factor of web services is governmental policies and regulations. I have experienced this first hand last year when I had to work on a project that dealt with personally identifiable information (PII) regarding US and Canadian Citizens. Currently the Canadian government regulates that any data pertaining to Canadian citizens must be store in Canada only. The issue that we had was that fact that we are a US based company that sometimes works with Canadian PII as part of a service that we provide. As you can see we are US based company and dealing with Canadian Data, so we had to place a file server inside the border of Canada in order for us to continue working for our Canadian customers.