Suppose you grant every nostalgic memory about the wonder of the Fifties. Stipulate that America was packed with happy prosperous one-earner families, cozily protected by their unions and patriotic employers. There's still one wee problem to worry about: nuclear war with the Soviet Union. Now there was a genuine existential threat. And it's gone for good.
[T]he total number of conflicts--international and civil wars--being waged
around the world increased threefold during the Cold War years, then
sharply declined, with this latter change going largely unheralded,
even at the United Nations.
The average war in the 1950s killed about 10,000 people a year; in the
new millennium the average was a little less than one thousand.
Fewer conflicts times less deadly conflicts equals massive declines in death. Mack's Figure 2:
And it is not just battle deaths that have declined. Deaths from
conflict-exacerbated disease and malnutrition have also been reduced by
long-term improvements in public health, notably immunization, that
have caused child and adult mortality rates to decline sharply across
the developing world over the past 30 years. These improvements have
not only steadily reduced mortality rates in peacetime but also saved
countless lives in wartime.
In addition there have been major increases in the level, scope,
and effectiveness of humanitarian assistance to war-affected
populations in countries in conflict. These interventions have reduced
wartime death tolls still further.
During the Naughts, insular Americans could easily imagine that the world was descending into a new dark age of slaughter. But you need a magnifying glass to see it in the data. Availability bias strikes again.
Oh ye pessimists, look upon the Great Pacification and despair!