I guess it depends on how you view peace, I believe that existence can only continue through balance and peace is only half of the equation. Looking at it from that perspective, peace can only come in intervals and the only true eternal peace is death. In order to end conflict, one must look at and put an end to what causes conflict. And what causes conflict? From what I've observed it's caused by necessity (i.e resources and space), desire, region, beliefs, differences, or simple misunderstandings. How do we address these problems? We could a.Make it to where we're all the same; same looks, same personalities, same clothes, etc. Or b.End the existence of mankind. For end order to end these causes we must end them at their root and mankind is the root of these causes. Yet even if we did manage to end conflict amongst our kind, it still wouldn't end conflict. For conflict is not the sole province of man, other creatures on this earth also war with one another. The conflict of Predator vs. Prey, Interspecies War, etc., so even with an end to mankind's conflicts; no matter how; conflict would still continue.
We need what is negative in this life to better know and appreciate the positive, they must exist in a balance in order for existence to continue. Without that balance there would be no existence. War and Peace are part of that balance, this does not mean that we should go spoiling for a fight and pick one at every opportunity, quite the opposite really. We should do our best to avoid conflict if we can, however should we find that we must fight then we should not be afraid to do so. This is what I believe, so can there be peace on earth as looking at it from my perspective? Yes, but peace is fleeting and fortunately... so is war. I accept that peace isn' ever lasting and never will be, so I appreciate it all the more while I have it. However I believe that if Mankind ever did find world wide peace, where there would be no conflict anywhere around the world, then Mankind's existence on this world would end. I don' know about you, but I would like to stick around for a little while longer. And when my eternal peace comes, I will gladly accept it; but I hope that it doesn' come for quite some time.