There's a story called "Memorial" by Theodore Sturgeon, from 1946, where humanity doesn't learn its lesson after the first nuclear war that is triggered by acci

There's a story called "Memorial" by Theodore Sturgeon, from 1946, where humanity doesn't learn its lesson after the first nuclear war that is triggered by accident. The ending (after the second war) referred to "half-stooping, naked things whose twisted heredity could have been traced to mankind." and said something about how, since they could be frightened, they were definitely not human any more.