The spread of democracy has become synonymous with peacekeeping since the end of the cold war. Any conflicts that the UN or NATO are involved in end with a generous push for the conflicted state to adopt democracy.
It seems to have been decided by all developed nations (with China as a notable exception) that democracy is the best way for a developing nation to ensure its people's freedoms and prosperity. This opinion is obvious in most of their foreign affairs and peacekeeping missions. According to Freedom House, a non-governmental organization, since 1972 the number of states with a system of electoral democracy has tripled from 40 to 123. It is speculated (Francis Fukayama's book "End of History" is a good example) that this trend may continue until liberal democracy is the universal form of human society.
Since homo sapiens' first steps, there have been several behavioral changes to our species that are so momentous and so advantageous that they inevitably spread across the entire planet, becoming adopted by every society. The first of these changes was the switch from hunter-gathering to food production: agriculture and cultivation of livestock. The change arose in several places across the globe at a few different times. Geographic barriers or a lack of domesticable species in an area sometimes limited its initial spread from these points. Those groups of people that did adopt these techniques enjoyed several advantages over those still living off the land. Most importantly, because they could settle down instead of wandering seasonally as hunting-gatherers do, they became able to store surpluses of food. These surpluses of food freed some people from the drudger of food gathering. These people, who would become warriors, inventors, or bureaucrats, were crucial for development by elevating mankind's thinking above where to find its next meal. Those groups of people who could develop this way were in a feedback loop, as each new development would further accelerate future development.
The next universal human change was the proliferation of writing. This spread took place much faster than food production, although once again it was not developed or shared evenly. Today, every nation has a language and an alphabet. The change to humanity is permanent: there will never be revolutions in which people denounce mankind's ability to write.
The rise of democracy throughout the world is quite similar to these two cases. Having won out against communism in the Cold War, it is now spreading. Ideas that sprang up during the Cold War such as the Truman Doctrine were refocused on promoting democracy rather than simply defending from communism. NATO especially, but also to an extent the United Nations, is controlled by democratic nations, to whom the mandate of "maintaining international peace and security" (the first chartered purpose of the United Nations) includes fostering democracy.
As evidenced by its continuing spread, democracy is quite advantageous to nations that adopt it. Its greatest strength is the way that it spreads out power, limiting the power of any one individual. Most are very open and encouraging of debate and opposing opinions. As a result, the personal motivations of a single person cannot hurt or in some cases ruin a country's future. Around 1500, China had a navy far superior to any European nation at that time. However, a single political decision, hai jin or "ocean forbidden", saw every Chinese ship destroyed and all ship building facilities dismantled. Its impossible to say what would have happened if this had never happened. But it is certain that under a democracy, such a decision would have been questioned, debated, picked apart, and then discarded.
Democracy's ability to listen to so many opinions and to promote free enterprise will allow it to become the norm for human society. The conflict in Libya and the recent rash of protests for democracy across the Middle East and North Africa are very obvious symptoms of the shift in human behavior towards democracy. It is important to recognize instances of this shift in conflicts today and tomorrow so that if any peacekeeping is done it will only ease the transition.


