Serious advice-guys perspective could be helpful?

So, I just got divorced three months ago. my ex and I have a child together. while we were married he repeatedly left us and came back. He punched me in the face and after two and half years I filed for divorce. I am with someone now( who I have known since I was 16) and my ex is now wanting me back. Saying he will do anything and even if i get married to my new boyfriend he will still tell me he loves me. My new guy is in Iraq and will be back in December. My ex has to come to my house for visitations with our daughter bc of him never being around she doesnt know him very well. The guy im with now wants to be a family man. He is crazy about my daughter. He is nice to me. Im torn. I want to make the right decision for my daughter, but I see no potential in my ex. He always says he will change and never does. Help Guys why is my ex doing this now?!Serious advice-guys perspective could be helpful?
Well for alot of people like this abuse be it sexual, physical, or emotional is a cycle. First the abuse occurs, it keeps going on until it reaches a breaking point, then the guilty party will apologize for said actions, and then after a while the abuse will occur again until it reaches a new breaking point. The answer is simple, some people just dont know how to let things go, you broke the cycle and left him and now he cant stand the fact that you have moved on. Now think about this really carefully, if this person was willing to punch you in the face do you really believe its best for him to be around your daughter. Your ex is doing this because he really wants you back, but if you take him back the cycle will continue, and you will blow your chances with what is seemingly a good family guy who is serving his country. You know what to do, dont be disloyal to someone who is trying so hard to do everything right. Instead stay away from the one who WILL wrong you.