I've watched this movie twice now and caught more of the nuances seconds time around. Yes the English subs were horrible but the dubbing was not bad. As to the question of why Id didn't save humanity, if we are their creations then they have the same capacity for war and bloodthirsty killing as we do, maybe even more, as well as greed and lust for power.
When the soldier dropped his weapon at the end of the movie it wasn't to show the alien children they we're not a threat, it was to stop the cycle.
Great concept and I like the way the Russian team handled it. Waiting anxiously for part 2.