Hi

"I am aware that using identical sites on two different domains is against Google rules"

Just to clear up a common misconception, this is not as such against Google guidelines. Duplicate content "penalties" are just a myth, unless you are seriously trying to manipulate search results for certain terms. Google staffers have on occasion even suggested duplicate domains (same content & language but aimed at different audiences) as a solution to the type of situation you outline.

However, whilst the theory is that Google will filter out the duplicate and return the appropriate site for any given search, that doesn't always happen in practice. There can be other disadvantages as well and often not a good solution but impossible to give specific advice without specific websites and an understanding of the business intentions.

Solutions can range from different domains to geo-targeted subdomains/subfolders, even duplicate sites with cross domain canonical tags on one if having that indexed isn't important but providing the local facility for users is.

All I can say is that the whole issue of running sites on an international basis is one that needs careful thought, much research and a defined solution for each individual business. In general though, putting the same or very similar content on the web more than once should be avoided if possible.