Robert Stone's "Dog Soldiers"

I am still seeking why this novel won the National Book Award. Right now, the protagonist, John Converse, is in Vietnam. He arranges for a shipment of heroin to be delivered to his wife in the United States and then she would sell it to the pushers. As it turns out Hicks, the person in charge to get the heroin to the U.S., turns on Marge (John's wife) and basically kidnaps her, her baby and the heroin. Again, I suppose it's a bit early to tell. I really had difficulties getting into it, but now the prose is really starting to flow. "Dog Soldiers" is not an easy novel to digest, but I will report later if it was worth reading.