Is the United Nations of today capable of preventing wars? What changes are needed to prevent wars and establish a peaceful world?

Have you ever been in a war zone? What was it like? What is your hope for the future?

Is war the only way to resolve differences between nation-states? How do provinces/states within mature nations resolve their differences without going to war, and why can't this be done globally?

What steps do you believe are necessary to achieve lasting peace around the world?