Another story it made me think of is 'Look to Windward' - the latest Culture novel from Iain Banks. The Culture war against the Iridians finished several centuries earlier, and everyone is trying to forget about the atrocities they committed. Then the light from the stars they blew up centuries earlier, with billions of lives lost, starts arriving at their home territories. So they can literally see what they did.
It's using the same FTL travel/nova wave front paradox, as a different kind of metaphor
Alison