Why does the u.s. force democracy down everyone throat?

Shouldn't people be allowed to choose what kind of government works for them? It's not like democracy is really a long term solution, look at the u.s. and its many social problems. If people prefer a Theocracy to a democracy, shouldn't they have the right to choose? Why does the u.s. feel it has the right to oust other governments at will, and install a puppet government?