I was reading this story-id request and it reminded me of story I read somewhere in the mid 90s to the early 2000s in an anthology. A scientist finds a way to explode the iron in the Earth's crust. I want to say that it was something like a Fission bomb, but with iron rather than Uranium. At the time, it reminded me of the story I'd heard of how, in early development of fission bombs, they always did air bursts because there was a fear that the nuclear reaction wouldn't stop, and might consume the rest of the Earth.
Anyhow, he reflects that, once the process is available, sooner or later, someone was going to use it, probably not a major government but a fringe organization or country who didn't care about the consequences. He considers destroying his research, but then reflects on an unhappy childhood, including a fair amount of bullying, and decides to publish.