In the short term, I favor a more isolationist approach to foreign policy. The U.S.- through its extensions such as the World Bank, IMF, and the military- has had a negative impact on developing countries throughout the world. Their sovereignty has been compromised by promises of aid. Hostilities have been heightened or even instigated as the United States sees fit.
Until we can get away from this policy of harming other countries because it seems as if it is in our national interest. We must respect the will and sovereignty of other nations.
Then, we must move away from the competitive attitude between nation-states. Each country should relate to each other as if they were states. Helping those in need should not be seen as an act of goodwill, but as a responsibility. Instead of dividing ourselves based on nationality, we should use the organization of the nation-state to improve the lives of everyone all over the world. If one country needs doctor, incentives should be set up to attract doctors to that locale.
The nation-state in not a fundamentally negative entity, but it has the capacity to be so. We must change it's purpose. The most powerful country in the world, the United States, has the power to do so.