World peace: yes it is possible
So why do we have wars? The answer has been the same for all of known history: a small group of elites profits from war, whether they are the people behind George W. Bush, Muslim extremist leaders, the Nazis, wealthy Romans, etc. Normal people do not profit from war but often their leaders and the elites in their countries do. The mechanism of going to war has also always been the same: dehumanize the opponent and spread fear among your own population.
The more I travel the more optimistic I get that with better communication, human consciousness will reach a higher point where self-serving leaders will loose the power to spread fear and dehumanize fellow human beings.