I do not believe that the only way to improve a country is to fuck over another one. That is the easy route most people take though. But not the only one.
The better a place to live your country is, the more people would want to live there. And since it's a country, it will try to keep as many of them out as possible.
That seems like flawed logic to me. You cannot make a single country a better place to live without making the rest of the world less so. It is still a self- and community-centric view on the world.