[metamemetics]

Straw man, argument 'self-defense == bad' not present.

Possible arguments:

1) The ethics (and humor) of pre-emptive strikes

2) Given that the proportion of resource-containing matter forming planets inhabited by sentient life to total resource-containing matter in the galaxy approaches insignificance, it seems extremely improbable that homo sapiens will ever be engaged in a competition for resources with sentient alien life at a time point where homo sapiens still exist and have not evolved into several other species.