Wow. This is a moving and dark sci-fi story titled “And the Heavens Wept” written by thefalloutdiaries about Earth, the third planet of a tiny system, surrounded by desolate space. Not one sentient species for hundreds of lightyears, and yet the humans managed to propel themselves into space. Eventually came The Interstellar War…
Source: thefalloutdiaries
See “With Friends Like These”, Alan Dean Foster. And lots of stuff by Gordon Dickson and Keith Laumer.
See also Larry Niven’s “known space” stories, especially “The Warriors” describing the first interaction between humans – thoroughly pacified to maintain society – and the aggressive Kzin. Even the least violent human can remember that “tool” can be a dangerous word.
https://www.baen.com/Chapters/9781451639001/9781451639001___5.htm
And can you imagine the bounty that would have been placed on those Texar-Hakara ships and personnel who took part in the burning of earth? The lengths that a Marine would go to in order to kill or destroy those?