First of all: it takes place in the 60s The soundtrack could be made of all parts of music from that era (e.g. the doors, Jefferson airplane, the Beatles, etc.)
Second: The beginning part was one of the best parts of any Tom Clancy book i've read, save rainbow 6, it could account for the drama, romance section of the book
Third: The middle to ending could be like a strategic Platoon when Clark is doing operations in Vietnam.
Who to play Clark? Dafoe is too old and even make-up can't hide that, maybe some rugged young actor, can't think of any