I'm sorry but this information is incorrect. The droid razr came with gsm support and was enabled in ics. Check out this
article for confirmation. teddyearp is correct, you should contact Verizon first. You will have to contact Verizon to get the phone unlocked and get information on Verizon international roaming plans. International roaming is very expensive, so I would suggest getting a SIM card from a local cell provider in Belgium and paying local rates to keep the cost down.
Sometimes Verizon can be a pain to get your phone unlocked, so be courteous and if the customer support representative will not unlock the phone, ask to speak to a supervisor or you can call back and a get a different csr who may be more receptive in getting your phone unlocked.
Have a good time in Europe, I have fond memories of the time spent there in the military...