One thing I'd change to make the world a better place
A world driven by a democracy. This seams unlikely in the world at it's present condition, which is filled with a wide variety of cultures and people. But if it was possible, I would abolish the various forms of government that seem to cause many of the problems, and replace them with a democracy. There are many aspects to be considered before such a transformation can take place. The place that democracy holds in national governments, forms of government it would replace, and things that would result of this transition.
One of the more prominent forms of governing would be the democracy. This system which is used by the United States and other countries like it, might be considered better because it allows the people to take an active role in dictating how their nation runs, and it does not funnel all the power into the hands of one person. However, in larger countries, the democracy tends to be a large, complicated system, which is very hard to follow. It's usually driven by one or more commities which are in turn headed by one person.
Dictatorships are one form of government, that have been put in a bad light by people such as Hitler and Stalin. These men used their power to do some very evil things and slaughter millions of people. But giving power to one person only makes him want even more power. Such is the case with the World Wars. Communism is a form of government in which the government owns virtually everything, your land, your house, your car, nothing belongs to you. Communism has become much less of a threat now as it basically ceased to exist during the late 80's.
Changing nations to make them work with a democracy is a little more difficult. Religion plays a major role in how a nation operates. For instance, a Muslim nation cannot easily operate under a democracy. They are accustomed to having one or few people ruling over them, or taking legal matters...