First of all I honestly believe that we all have free will to choose, especially in the USA compared to the rest of the world. Sure, some people convince themselves that they are doing what they want to be doing, but in reality probably never pursued their true dreams or "discovered"what they were "intended" to do in Life. (But that takes your question further.)
After reading your little story, this is how I percieved it: I associated the father soldier as Life. Life is always pushing us around, kinda telling us here and there "what to do". Now maybe Ray had a talent to be a soldier? And just becuase he didn't "want" to be one at times, doesn't mean that he wasn't intended to be one. Now, the story is very simple and doesn't answer alot of questions. But, I believe that in life , we all have a purpose here. Whether we find out what it is, or even decide to act on it, is another matter.
Now, if Ray knew he wasn't intended to be a soldier, then he couldn't have honestly declared it was free will to be one. And then the story would've been set up fool the reader.
Think about it: if you have no purpose in Life, then WTF are you good for? Not to mention why the hell are you here in the first place?
I know you're being devil's advovcate on this issue,...good topic, lets just take it further.
"If one advances confidently in the direction of
his dreams, and endeavors to live the life he
has imagined, he will meet with a success
unexpected in common hours."
- H.D. Thoreau