There's probably no greater disaster imaginable than a world war fought with tactical nukes, cyberattacks and bioweapons. It's an idea that we haven't taken very seriously since the Cold War. But when the World Economic Forum asked experts across a variety of fields to name the most likely, worst outcome of the next 10 years, guess what they picked?
The reasons are deeply enmeshed: food and water insecurity, climate change, financial crises, infectious diseases and profound social instability. Add rising nationalism, dubious territorial claims by major powers like China and Russia, Japanese militarization and a pinch of terrorist pseudo-states, and a fearsome picture begins to emerge.
Of course, one could argue that our global connectedness militates against any large-scale conflict; we simply would lose more than we gained. The U.S., China's biggest product consumer, and China, America's banker, share an economic suicide pact so tight that some have nicknamed it MADE (mutually assured destruction of economy). That said, entangled powers once made World War I unthinkable, too, and its major players had a lot in common.
Then again, they didn't face the prospect of nuclear extinction. Nor did they have our access to satellite intelligence and instant communications, assets that help limit misunderstandings. So, on balance, a third World War would be irrational but not impossible. Why doesn't that make us feel better?