First, you can't wait until war is declared to start building an Army, and what is a "no-exceptions draft"?
We can build up all we want. Just keep them home unless Congress formally declares war. A WW II draft would be in order.
The nation has to be fully committed. Not like Korea, Vietnam, Irag, Kosovo, Afghanistan. And Obama should get such a declaration of war before he bombs Iran by enforcing his 'all is on the table' dictates.