How to design an application for different countries? [on hold]

I am trying to develop a .NET 3 tier application that will be customizable based on the country it will be deployed to…so it will have different data model for different countries. From the design perspective,

1) Should I create a database per country? 2) How should I structure my application so that all the code is in the same codebadse except perhaps data accesses part as nuget package?