As much as America is a stable democracy a quick google search will easily demonstrate their is more resource project investment in countries of Africa , Europe and Russia. One must be selectively in the country in Africa you invest i.e. Angola, Congo, Leone for instance.
South Africa, Tanzania are home to some of the biggest and longest serving resource projects worldwide.
Resource projects in the US dont get built for the same reasons as other parts of the world i.e. high costs, lack of funding, bad resource economics.