Taking a long term view of humanity's 100,000+ history, in the last 50-100 years there has been abrupt transition into less war,with the remaining conflicts persisting in relatively small and isolated pockets of humanity. The Nuclear Age forced humans to act out their ambition and aggression toward each other through increasingly more discrete forms of conflict, mainly economics backed up by the simmering threat of violence. New technologies obviously play a large role in this, with the benefits of peaceful economic development far exceeding the potential gains of nuclear war.
However, populations are growing and Earth's economy driving resources are set to expire in a couple hundreds years. In a few decades, missile defense systems and tactical nukes will make nuclear war nowhere near the threat it used to be, which means ambition and aggression may come back bubbling over the veneer of civility.
I guess the thrust of the debate is -- will humanity's rapid technological development empower us to recycle our Earth-specific resources and farm the stars fast enough to outpace the ravenous demand of the world's billions for more resources right now? If the answer to that question is, 'no', then more wars seem inevitable at a glance.
No matter how different modern life is from the past, we still have the same genes as the people who existed in the 99,900 years prior to us.