Embarrasing
My son would have been horrified if I did that at his B-day party - not really into making a craft at a party at that age. He would not been too happy to wear a badge and pretend he was from another country etc...
He preferred that I gave them a ball and sent them in the backyard to play some sports or put on a good movie with popcorn or something like that.
With that said, keep in mind every kid is different and every locale is different, so maybe the boys in your area would enjoy the type of party you are thinking about???
PS: as a parent - I would not be offended by that. I certainly wouln't think that you were making "real" fake i.d.s to take them to a bar, as someone suggested.