Relations with the Vyusher R'asa have gone through different stages over the years. Since Xeph's rise as Alpha, they haven't been overtly hostile. Xeph himself, while not opposed to violence in certain situations, will choose peace first and foremost. Therefore with him in the lead the Kadzait tend to be reactive rather than proactive. Xeph will not condone violence against another werewolf when it is instigated by a member of his own Pack. He will, however, support it if there is ample proof that it was done in self-defence.
The same goes for vampires. Although less inclined to trust this race, Xeph is nonetheless more interested in the continued peaceful existence of his Pack than in any age-old vendetta, real or imagined. He does believe, however, that his race has been oppressed and poorly-treated over the years, and with recent discoveries and enlightened understanding of vampires' continued involvement in the Kadzaits' (and all werewolves') history, Xeph may be more inclined to be more lenient in cases involving vampires.