Book 1 in Leslie Gadallah's trilogy of interstellar intrigue, The Empire of Kaz
The Kazi Empire is slowly, inexorably, expanding up the arm of the Galaxy. Only the Oriani see the danger, and only Ambassador Talan recognizes the need to include humans in the alliance to oppose the Kaz.
Unfortunately, in the chess of interstellar diplomacy, humans make terrible pawns . . .