Sixty percent of the American public already doesn't trust President Donald Trump with nuclear weapons. That number could be about to rise.
With the most powerful conventional and cyber military force in the world, the United States has no need to respond with nukes. But others might. Thus we should be working toward a global norm against nuclear use, not lowering the nuclear threshold. Moreover, cyberattacks are particularly hard to retaliate against, since it is difficult to definitively establish where the attack came from.