My daughter is in the military. She is getting married this fall and is worried. If she is sent overseas on a remote tour (lasting 1-2 years) can her new husband get a passport, will he need and be able to get a visa? He was convicted of a felony 12 years ago at age 18. He served his sentnce and completed his parole.

He can of course always get a passport, that is merely a form of ID. Getting a visa will depend on the country they are going to, some will not allow him to go.

Also some assignments in the military do not allow spouses to go also.

All correct, he can certainly get a passport but some countries will deny him entry, certain countries may have a program for him to apply for entry based on this being an old conviction that he served his full sentence on.

This will have to be done case by case as your daughter is informed where she will be stationned (and if they will allow him to follow)