What is a word or phrase to describe people who are very practical and shrewd, and more concern about achieving their goals rather than looking at softer sides such as friendships, etc? It is more than just self-centred. It is a kind of character which one who inherits it would not hesitate to do very shallow acts just to emerge as a winner/survive, even if he has to betray his benefactors. It is a very insecure kind of character but on the surface is not obvious to be like so.
For example, Tom befriends with Jane in hope of her help at work. Jane helped Tom. Tom, however, may possibly make Jane his enemy one day, when he knows his boss dislikes Jane, so as to appear standing behind his boss.
So in some way, Tom in this scenario, is a what kind of person? In casual words, he is practical, shrewd, self-centred, etc. But is there a more concise word that encapsulates all these words and brings about the idea of such a character?