...are many but highly ambiguous. Some historians would even deny their existence.
History Does Not Repeat Itself, But It Rhymes.............attributed to, but quite possibly not actually said by, Mark Twain.
One lesson I'm pretty confident of, however, is that humans have a strong tendency to assemble themselves in rival groups and kill each other. My confidence is considerably increased by the collaborating evidence from anthropology, archaeology, biology, and psychology. That tendency has always been a source of endless grief, but since the advent of nuclear weapons, has become an extinction level threat.
Historically, the best remedy for interpersonal violence has been a state with a monopoly on violence. Only a global state, or something like it, could work when every two-bit state gets nuclear weapons. Such a state is unnatural to human instincts, and anathema to nationalists of every stripe, so highly unlikely to happen. Unless our robot overlords decide that it's necessary.