Right, just like if the good guys don't develop a novel coronavirus in a lab, the bad guys will and unleash it on the world!

Development of tools of death is not a good guy/bad guy thing. The "bad guys" think the "good guys" are bad.

I think "killing" is bad, no matter who develops the tools.

There are certainly times when killing is justified. Defeating the Axis in WW2 is a great example of this.

Hundreds of thousands of innocent civilians died in strategic bombing campaigns to achieve that outcome. Do the ends justify the means?

Yes, without shred a doubt or hesitation.

Germany and Japan were killing millions of innocents in WW2. Not only that, but those killings were entirely unnecessary.

At least with Israel I can give some of the benefit of the doubt that their civilian casualties have some strategic outcome. You cannot say the same of Germany and Japan in WW2.

(please be charitable to the above; there is a lot of nuance here; I don't want to explicitly spell it all out. look at my other comments if you want to know my views)

It's just that I fear their strategic outcome will in the end become a net negative, for everyone.

I believe the Allies could have defeated the Axis with less collateral damage.

The ends were admirable. The means are debatable and in some cases regrettable.

This assumes that AI based weaponry provides value. The case in point here is showing that the only value it provides is a flimsy justification for civilian casualties. We... Don't need more of that in the US, nor would it provide a "good guy" any legitimate value.

"Good guys" and "bad guys". Where did you learn your ethics, the Cartoon Network?