There is optimism behind these questions. If technology stopped developing today, or even dropped to a linear rate of expansion, there would be every reason to expect the American Republic and her sister democracies to slide into collapse followed by dictatorship. However, technological innovation and discovery continue on an exponential development curve. As Diamandis says, we are not wired to understand the implications of exponential growth. In predicting worldwide abundance, Diamandis and Ridley and a few others may see more clearly than the rest of us. And because innovation both depends on and empowers liberty, it is plausible that our future will be both abundant and free. Most of us will squander that freedom; but not everyone. In any case, continuing to apply a moral or historical touchstone to current events, like a latter day Livy or Machiavelli, may be wasted effort under the regime of accelerating change. Even Heraclitus is an inadequate guide.
This is not to say peace will break out all over, or that we will enter a Star Trek future without war or poverty. Yet even here, Steven Pinker has documented a persistent, worldwide decline in violence across a relevant historical period, and nothing about his evidence is obviously invalid. There will be pain and crime and misery for many people for many years to come; but the old demons no longer have power to dance in all our dreams. The nightmares are on the wane, and we sleep much better after we look past the headlines and see what is happening unnoticed by the purveyors of despair on the Left and the Right. Really, it is a splendid opportunity to be alive just at this point.