Yes, there should be peace and harmony for every living being, because all living things were created by God. God intended for each human, as well as animal, to live in peace. Of course, this cannot happen in this world, but humans should show each other as much love and kindness as they possibly can.
Peace and harmony for everyone is a great goal. The problems begin when you have reckon with the fact that not everyone wants peace and harmony for everyone else. They want this for themselves and their people, but their definition of peace and harmony might require just the opposite as a means of acquiring it for themselves. This is often related to differences in religious beliefs and racial divides.