A Savage War of Peace — Christopher G. Nuttall

On her maiden voyage, HMS Warspite discovered Vesy, a world populated by primitive aliens, aliens whose culture had already been twisted and warped by human refugees from the First Interstellar War. Now, Captain John Naiser and his crew spearhead a diplomat mission to the alien homeworld, hoping to ease them into the galactic mainstream. But with hundreds of others hoping to influence and shape the developing alien culture, and all hell threatening to break loose as human ideals meet alien realities, events on Vesy might just mark the start of a new interstellar conflict ... ... And a civil war that will tear the human sphere apart.