Send Down the Rain by Charles Martin

An American fellow who was drafted for the Viet Nam war, left his girlfriend and went to Asia and risked his life many times. Received many medals, but became almost a recluse when he finally returned. He has a gift of starting little companies and making a lot of money.

But he has secrets that he carries.

I liked the story, but from about the second half of the book I felt that it was a bit "over the top" and not believable.