The song is all about imagine there are no countries. Imagine no borders, no barriers between each other. And so no reason to start wars and start fighting, no tribes. Why after half a century does the world still not understand the meaning of the song imagine? Oh, well. Because it's an ideal. It's what the world should be like. But it seems that human beings aren't able to achieve the ideal. When things are good, they just destroy them. That seems to be my experience.