if there is life on other planets, i'm sure the implications with someday include war. we'll have this brilliant idea that they're out to get us and we'll try to annihilate them. happens all the time here, why would it be different with other planets?
if one were to assume the judaic creation myth(s) true and consider the implications of these myths on other planets, i'd assume that god would be sonsistent in his creation and create decision making creatures capable of becoming falible. and, i'd imagine they'd end up in the same boat we are. and maybe they'll declare war on us first.
the other possibility is that maybe they are without sin. if this is the case, we could introduce sin and death to them. or perhaps they are immune. the first would, i imagine, carry a great eternal toll.