They say history is good predictor of future behavior. The Americans sought to minimize ground troop casualties by using nukes on a civilian population which they viewed as expendable. Today, their first strike doctrine is troubling to say the least, and it seems they are lowering the bar year after year.
"The US has not only argued that it can use pre-emptive nuclear strikes against non-nuclear weapon states, but recently has also argued that even a cyber attack
on the US could trigger a nuclear response."
Compared to a more sane position:
"China has a theory of credible minimum deterrence. Unlike the US, both Russia and China have always declared that they will not use nuclear weapons unless attacked with nuclear weapons first."