TLDR: smarter targeting allows the same explosive power to be more effective.
This general principle has been known for a very long time. These are the same people who put out the totally useless "Doomsday clock" and like the "Doomsday clock" are just trying to stir up fear.
We've also seen how it has turned out in Syria, Iraq, Afghanistan, Vietnam, Libya. Hundreds of thousands of people dead, for nothing. But as long as it's other people dying, we're totally fine with that.
Strawman. None of those involved genocidal maniacs (unless you include Cambodia, where the U.S. did not intervene) nor plain old tin pot dictators bent on world domination.
> I want to live in a world where instantaneous human-caused planetary disasters cannot happen.
That may very well stay in the past (until the first such disaster) - the whole point of technology is to have ever finer control over ever more powerful things. Two big subsets of that are ever-increasing energy demands (energy = destructive power), and self-replication (aka. biotechnology).
This general principle has been known for a very long time. These are the same people who put out the totally useless "Doomsday clock" and like the "Doomsday clock" are just trying to stir up fear.