Boyfriend leaving to basic without proposal

My boyfriend is leaving to basic training in a month. He will be gone for 4-5 months. I expected him to ask me to marry him before he left, but last weekend he said he had a surprise for me this weekend. So naturally I thought he was going to propose. But it ended up just being a gift card. I was devastated.

How can he leave without "sealing the deal"??

I expressed my disappoint to him. He explained that he doesn't want to get married until he gets back because he wants to make sure that a military wife life is the life I would want. And I understand his reasoning. But if I didn't want it then I wouldn't be with him right now.

So I guess my question is is it right for him to make me wait or is he just stringing me along? I don't know what to do! If we do wait he will only be back for 2 weeks, so we would have to get engaged, get married, and move to base all in 2 weeks!