The principle of NATO, is that an attack on one, is an attack on all, and there is an obligation for all members to help.
If NATO members failed to mobilise to help a fellow member,then it will discredit the whole concept, and the commies will be chuckling in their vodka before goose-stepping their way across Europe and the middle-east.
But, the Georgian presidents' "Nah, Putin will never bother to help the South Ossetians" will be up there with the Mayor of Nagasaki's "WTF was that bang?"