I dunno. That might be true. But I'm not too sure.
Think about our flights to the moon. We had the tech to get there, but frankly we couldn't do a whole lot with what little equipment we were able to actually set down on the moon. If people had been living there, there's no way we could've took over the moon with just a few guys in an Apollo landing craft.
And if aliens do show up here, we should shoot them on sight. Look what happened to the Native Americans when they didn't take out Columbus first chance they got.