One perspective overlooked here is the purchasing power of non-Americans (i.e., not U.S. citizens). Dollars in developing countries can be worth multiple times what they are in the United States. For example, you could help 5000 rural Vietnamese for every 1000 rural Americans. There is also a higher potential for rural Americans to obtain dollars vs. non-Americans. In utilitarian terms you have the potential to do more good by sending money to rural communities overseas.
I'm saying this as someone who loves Appalachia.
