I knew someone, dead now, who had run off to the White Mountains rather than serve in WWII. He was a German American twice removed, and a German sympathizer.
We will probably have to turn into the Balkans before we really take on this issue.
And, until we seal the borders, internment won't help anyway. I've told the story here before of "HR's Mom and the Nazi Spy", but basically, during WWII, a very tall, blond, blue-eyed, square-jawed young man appeared at my grandma's door on the ranch they lived on near Laredo, asking for food and wanting to know where he was. My mom was very little and was clinging to the back of my grandma's skirt as she stood in the door. It was Spring, and this guy had on a winter coat beneath which he was concealing a large, boxy-shaped thing. He spoke even better Spanish than my grandmother (not an easy accomplishment) and pulled out a thick wad of American currency as he asked for food (nobody that ever stopped at her door had that kind of money). She put a biscuit and some food on a plate and pushed it out the door to him and said "no charge, just go away". When my grandpa got home from cowboying that evening, she told him about it. Later (after dark) some little boys came by to tell my grandpa they'd seen a strange man who'd built a fire in an old ruined frame of a barn and they said he was speaking a strange language into a boxy radio. My grandpa looked at my grandma and said, "I'm going to tell some of the other vaqueros (cowboys). I'll be back later." When he got home much later that night, he wouldn't talk about it except to say that they'd "taken care of it".