The Pacifist's War, Book 2 in the St. Germaine Chronicles
by V. M. Franck
Losing himself In Vietnam, Peter embarks on an amnesiac's quest to uncover his true identity. Wearing a name which is not his own, he is alarmed when he receives medals for atrocious acts he could not have committed. His search for himself leads to a cave, encrypted writings, a dog named Emmanuel, a mysterious woman, his sister Arranah and what remains of his family.