World peace: yes it is possible
I just returned from a trip to Belize and Guatemala. Visiting other countries always reminds me of how similar people are. I believe that spiritually we are all bound tightly together and on a practical day to day level we all want the same thing: a better life for our children, a safe environment to live in, and time to spend with people we love.
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.