When Duty Calls — William C. Dietz

As the war with the Ramanthian continues, Captain Antonio Santana and his force of biobods and cyborgs find themselves surrounded by enemy forces, faced with annihilation at every turn.

On the home front, Santana's love--diplomat Christine Vanderveen--copes with growing shortages, treacherous allies, and her own emotions. Yet when she meets the charismatic newly elected president of the Clone Republic, she finds herself torn between old love and new loyalty.

As Christine fights her own divided heart, light years away, Santana is in a battle for his life. And this battle may be his last?