Interracial unity

Why do we need to fight, if you and I are brothers and sisters? I  am curious of why does other nations fight with the other nation. Don't they know that we are one? Why don't we just stop fighting and make the world a better place. Accepting everyone in our community is the best way to understand what others want to express out. If only I can make the world peacefully, then I will gamble my life to do it. I wish people from different countries, understand the expectations of each and everyone without tresspassing the limitations and the boundaries of each rights.