Mandy,
Unfortunately there is absolutely no doubt that this is a scam. PEOPLE WHO ARE NOT IN THE ARMY CANNOT REQUEST LEAVE FOR A SOLDIER, AND THERE ARE NO FEES TO BE PAID FOR LEAVE, EVER.
The photos you were sent are a real man (who is very likely married or in a relationship) and a real boy (who may be the real person's son or may just be a child model if there are no photos of them together). But the man who is talking to you has no connection to either one of them and doesn't even know them. He just found their photos on the internet and copied them so he could use them in his scams. The man who is talking to you is a young African man, who has no connection to the US Army, and is writing the same kinds of lies to several women at the same time.
The general is not real. He is an African man, and is either the same person as the soldier, or is part of the same scamming gang.
I know this is difficult to hear, but it is the truth. The scammer will continue to lie to you. He will claim that he is real, he is innocent, that we don't know what we are talking about. He will try to make you feel guilty for doubting him, and pretend that he is hurt and sad and will love you forever. In the end, he may even "confess" and say that he did it all because he loves you. The fact is, he will say ANYTHING he thinks is necessary, if he thinks there is any chance he could get more money from you.
why would anyone be so cruel
Because he doesn't care, plain and simple. His goal isn't to be cruel--it is to get money from you. He doesn't care if he hurts you (or his other victims, because there is no doubt he is scamming other women too--maybe under the same name, maybe under another.) He copies romantic poetry; he calls you "babe" or "honey" or something like that; he says whatever is necessary to convince you that you are in a relationship. He doesn't care what he has to say--his whole goal is to convince you that he is real, and to make you believe that you are in love enough to send whatever money is asked of you.
You need to cut off contact with this person and anyone associated with him immediately. There is a link in my signature with more information for victims--I strongly encourage you to read it. I know this isn't easy, but hanging on is only going to hurt you more in the long run.