If the second patent is identical to the original patent I would say that it is invalid as it would not meet the "novelty requirement".
If no patent exist in the jurisdiction where the second patent has been granted there would not be patent infringement. Patent infringement would only occur if the protected product is sold/used in a country where the original patent exist.
The fact that the patent has been granted does not mean it is strong or even valid. In most instances, intellectual property offices grant patent without thorough technical examination which means thousands of patents are awarded each year which in fact can be invalidated quite easily. Check the text of your patent: it usually is written quite plainly that it is granted "without any guarantee" of the state as to its validity.
That is why relying on professional help is very important: patent attorneys and lawyers will research existing patents, will help you draft the text of the patent and ensure that the delivered document is strong and will not be invalidated if a third party challenges it.