Should I call or email my boyfriend (I guess ex now) to find out why he dropped out of my life?

My boyfriend is in the military and he was recently stationed in Mannheim Germany. When he first left we were communicating by phone and email on a regular basis. I then proceded to visit him in Germany over the holidays and things went well in my opinion except for a few moments of disagreement. When I returned home he started calling and emailing me less. However, since the time that I met him up until the day he decided not to contact me anymore he professed that he loved me with all of his heart. I am so confused about love right now and so hurt by him but I have this need to know inside why he "left me" (if you will). I have all of these insecure thoughts that he found another woman, that I wasn't compatible with him, that I was boring or something. I feel like I have this need to know his reason even though I'm not sure that is the right decidion. I want to know if one would suggest I contact him to find out his reason(s) for leaving? Or, should I just leave it alone and go through the pain necessary to move on? Finally, why would anyone profess love for someone only to ditch them 2 days after the last time they said it?