Much as I asked the other commenter, how many school shooters would need to be in the school before we believe it's valid?

Let's change the analogy: ISIS terrorists take over the MIT campus. Inside the university are 50 armed terrorists. Is it valid to now bomb the university? What if there are 100 terrorists?

There is no issue with scale here. No matter how much it scales, you won't reach a point where there is an ethical position that argues for the mass murder of people that we actually view as people. It only becomes ethical when we dehumanize the people affected.

Maybe about 3000 terrorists? Is this a Beslan like situation?

So what do you think would happen if terrorists took over the MIT campus, students sympathized with them, rockets were launched from it, and the US police had no presence there and very sparse intelligence?

> students sympathized with them

So we're back to 'all of them are guilty'

The shame here is what you described is literally Hamas' reasoning for carrying out the October attacks. Dehumanization, hyper aggression, and hiding it all behind 'the opposition is inherently evil, guilty by association, so we are fundamentally justified'.

Yes, there a lot more civilians killed in Gaza every day than you could fit into a school. What Israel does is much, much worse.