you maybe miss the point of what the USA is, and where it sprang from
for 1000 years, Europeans tucked themselves away behind their ramparts. The Italians behind their Alps, the Spanish behind ther Pyrenees, the English / Irish across their moats.
They ventured out and fought each other once every generation or so, but bows and arrows and muskets didnt do much long term harm.
Suddenly a new land opened up — -and all these races were thrown together, not only that they were fully armed with modern weapons, there were few constrainsts about using them
It was the promised land, each race wanted a bigger slice of it, just as they had in old Europe, But in the USA they never ran out of ammunition, or prejudices.
They inflamed them with racial and religious dogma, and were willing to kill one another.
But land and open spaces were plentiful, so infinite expansion took the heat off the urge to slaughter each other. At least for a while.
Now the land is full — -no more opportunity for new frontiers. So the killing becomes inevitable, and will increase because the cause for killing now is denial.
it cannot be that expansion is over, so the violence and killing is an expression of frustration and anger. a denial that the promises are never going to be filled, the candle has finally been burned from both ends.