From the original manual:
"Vanu Sovereignty - The destiny of the human species tilts toward ruin. Thousands of years of shortsightedness and provincial thinking have hampered its proper evolution. We plunge towards oblivion. Those able to comprehend the promise and potential of humanity will advance. They will usher the less gifted through the gateway of understanding and cleanse the taint of blindness, ignorance and mulishness from the species. We are the shepherds of evolution, the harbingers of progress. We lead toward the light."
Good enough reasons to wage war in my book