A.E. van Vogt, The World of Null-A, in the Triad omnibus pages 157-158

"The treaties forbid the use of atomic energy except as a source of power and for a few other specified purposes. We destroyed the Machine with atomic torpedoes. True, they were very small ones, but atomic nonetheless. In the League lexicon, the greatest crime of all is genocide. If you kill five per cent of a population, that's war. If you kill ten per cent, that's slaughter, and subject to indemnities if you are convicted before the League. If you kill twenty per cent or twenty million, whichever is greater, that is genocide."