Question

why is democracy spread

Answer 1

And electoral democracy cannot function effectively outside political units such as nation-states. ... The effort to spread democracy is also dangerous in a more indirect way: It conveys to those who do not enjoy this form of government the illusion that it actually governs those who do.

Answer 2

We are at present engaged in what purports to be a planned reordering of the world by the powerful states. The wars in Iraq and Afghanistan are but one part of a supposedly universal effort to create world order by "spreading democracy." This idea is not merely quixotic — it is dangerous.