I know this is the "theory" that is supposed to reject all other previous theories of International Relations, that it emerged from an aversion to modernism (or the idea that truth can be objectively derived from science), I also know that it the definition of postmodernism is highly debatable, but could anyone explain to me how exactly this theory can be applied to foreign policy? It just doesn't seem to be a school of thought that is particularly applicable to real policymaking criteria or to real world events for that matter.
For example, how could anyone explain American foreign policy through a postmodernist approach?