Ok, here it goes....
We fear what we dont understand. and no matter what we are, we destroy what we dont understand. THis is my theory. The shivans had watched, fors thousands of years, species fight each other. They watched, and as their fear grew, so did something else. eventually they cracked, from the ancients entering their borders. They knew the ancients would destroy them easily. They cracked, all the fear turning into hate and anger. They hid away, deeper into their territory, making weapons, waiting for their chance to strike. They destroyed the ancients. THey had learned how to fight.
THis theory gets its designation from the word Xenophobic. It means (i looked this up) that they are hateful and Frightened of foreigners and strangers. as i explained, the fright leads the misunderstanding, misunderstanding to war. The shivans destroyed any species that got too close to their borders. Then came the TV war. The shivans watched as the terrans and the vasudans fought each other in extremely bloody, bitter battles. (

hate that) They tried to eliminate the threat. But the Terrans and vasudans were powerful, and and when allied they were able to defeat the shivans.
THis defeat brought more and more fear and anger. The shivans recoiled, then attacked again. I fear they will not stop until the GTVA has been wiped out.