The question is: what is the problem you want to solve?
- Do you want to prevent your users from accidentally un-localizing?
- Do you want to make it possible for them to undo an earlier un-localize action?
- Do you want to keep the history for auditing purposes?
- A combination of the above?
Note that these problems may have different solutions, so it is good to know which problem is the most common and urgent to provide a solution for.