 He has stated that whereas the greatest threats to the "open society" in the past were from communism and fascism (as discussed in "The Open Society and Its Enemies" by his mentor Karl Popper), the largest current threat is from market fundamentalism.He has suggested that the contemporary domination of world politics and world trade by the United States is a reflexive phenomenon, insofar as the success of military and financial coercion feeds back to encourage increasingly intense applications of the same policies to the point where they will eventually become unsustainable.Soros argues that the current system of financial speculation undermines healthy economic development in many underdeveloped countries.