Throughout the Ender series, of course, one of the main topics in the book is destroying the various species. Are you trying to convey to the reader that it is alright to destroy a race to insure human survival? Or, are you trying to take the other approach by telling us that it is wrong to do this?
I'm trying to tell people that it's a very hard decision, but that a species has a right to do what is necessary to protect its own survival. In human history, however, the decision to commit genocide has usually come, not because it was actually necessary to destroy the enemy utterly in order to survive, but because the rhetoric of dehumanization got so heated that there was nowhere for it to go except murder. That was the rhetoric of Nazis and most present-day Islamic nations about Jews, it was the rhetoric of Hutus about Tutsis, and it was the rhetoric of Christian Serbs about Muslim Serbs. The challenge to decent people is to recognize when the danger is real and there is no alternative but destruction.
I wonder if there has ever been a time in human history when utter destruction of an enemy was required. Usually all that is required is the destruction of an enemy leadership that seeks genocide against you, and then decent treatment of the replacement government. We've had two generations in which warlike Germany and warlike Japan have been at peace with their neighbors because that is how they were treated by us. And it is quite possible that the story of Iraq, Afghanistan, and even Iran will end similarly, by one road or another.
But what depresses me deeply is that the Islamic rhetoric about Israel and Jews in general is so false, so evil, and so universally pounded into the Muslim people in most Muslim nations that Israel may well - indeed, may already - find itself in a position where completely unjustified and virtually unprovoked genocide is committed against the Jews - or, in order not to die as a people, the Jews have to commit terrible acts of war against their enemies. It is hopelessly unnecessary to have this situation, which is caused by leaders stirring up hatred about an all-purpose enemy in order to shore up their own unworthy regimes.
In the Ender series, however, we're talking about interspecies conflict, not intercultural. And because species would be far more different than cultures, the dangers are far greater. We have, in fact, destroyed or nearly destroyed other species before - sometimes unwittingly, sometimes through criminal negligence, and sometimes through deliberate action. If someday one of these species might be sentient as we are sentient I do not know if that will slow us down from the strong possibility of such a murderous course of action. And yet ... IF we met such a species, and the only way to stop them from destroying our genetic heritage completely were to destroy theirs, then I believe, morally, we would be completely justified in doing so. At the same time, we have the moral obligation to make sure that we do not pose the same threat to others.
War of any kind is a terrible thing, but communities, and species, have the right to protect themselves from destruction, enslavement, or other dire threats; and in the struggle to save themselves from aggression, they cannot be expected to use only the exact amount of force required and no more, since it is always impossible to know just how much force really is required. Since one's own destruction is the result of guessing too low, the natural response is to guess too high, and a nation involved in a defensive or protective war cannot be faulted for guessing wrong. Nor, for that matter, can a species. So in Ender's Game, though I assign responsibility for the near-destruction of the Hive Queen (and Ender takes it upon himself), I do not assign blame, because I don't consider there to be any blame. You can't be held responsible for not knowing what you could not know at the time of a crucial decision.