The Man in High Castle - Science Fiction

What is the difference in emphasis between the terms science fiction and speculative fiction? Which is The Man in the High Castle?

First of all i am going to address the meaning of speculative fiction and science fiction.
Speculative Fiction
Speculative fiction is a term based on a broad literary genre encompassing any fiction with supernatural, fantastical, or futuristic elements (Dictionary.com, 2015).

Science Fiction
Science fiction is a term mostly based on imagined future scientific or technological advances and major social or environmental changes, frequently portraying space or time travel and life on other planets (Wikipedia, 2015).

The Man in the high castle seems to fall under both science fiction and speculative fiction, however, i would suggest that the Man in high castle is more of speculative fiction. For the reason that the story of the Man in high castle presents historical and futuristic elements as it is about World war 2 (WW2) portraying America as the defeated country against Germany and Japan.
The man in high castle refers to real life historical events as it reflects on the events of WWII and even mentions the involvement of certain individuals/countries. 
The novel of the Man in the high castle takes a different approach from science fiction novels as it takes the audience into an alternate history, the novel is a presentation of what the world could have been if the events had ended with the opposite outcome. 

Brown (2001) stated that mind of characters and another world of this novel in close relationships even can't expect the fate of the world without the understanding of individual characters. 
In the statement of Brown (2001), i think he is trying to credit Philip, K., D. with creating a novel that shares historical and futuristic elements. Dick (2001) was able to imagine the world in a different setting if WWII ended differently. 

Dick (1962) presents the WWII events in the story of the man in high castle as an alternate outcome of the actual WWII, Dick (1962) does this by illustrating how the Axis Power wins WWII, "the world presented here is but an illusion so that other better worlds might exist. p5 (Dick, 2001).
 It would seem that Dick somewhat speculates in this novel on what could possibly happen in futuristic terms. Which would then lead me to believe that the man in high castle is set under speculative fiction. Though i can not be entirely sure cause it would seem like the man in high castle could also be a science fiction novel as well. 

References

Brown, E. (2001). Introduction. In Dick, P.K., The man in high castle. (p.v-xii) London

Dick, P., K. (2001; 1962). The man in high castle. London: Penguin.