Maybe I'm being pessimistic, but we might find ourselves in such a situation that the only practical solution would be to use agents to counter rogue agents. This won't be without collateral damage, though.
If fighting AI with AI is pessimistic, I don't know what optimism is. That sounds like optimistic to me...!
Your view sounds more optimistic than mine, honestly. I expect that we will fail to make any serious, coordinated attempt to solve this problem. Then we'll either live or die due to fundamental principles that we currently have no insight into.