PEOPLE has to change,then politicians change also,50%  of americans agree to invade some country to get the oil needed...
people want war...

None of the above.  It's all about money and two classes of people:

money is invented by PEOPLE ,so if people want to change they find a better way of living and using the recources.
as long people want more than the neighbour there will be wars.
money is only a means of getting more than the neighbour.