World War II actually gives me some hope. Because as savage and brutal as that war was, as awful and terrible as the goals of Nazi Germany and Imperial Japan were.... they didn't win. That future that they were trying to create, it didn't come to pass.
Progress is slow, but possible. Human beings aren't inherently good or bad, but we inherently form order and societies over time. Humans are communal creatures, for the most part. My feeling is eventually, given enough time and the right conditions, there's plenty of hope for our species. Look at how far we've come, when you look back over the centuries. Women can vote. Slavery is official detested (although still practiced, sadly). War is, with few exceptions, no longer openly glorified. Murder rates in the developed world have plummeted. Science and technology have allowed us to understand ever more about the world.
The world has a lot of evil and heartlessness in it. But it has good people too, and our species has potential. Whether or not we'll use that potential, well, that's up to us and history. But it's there.