If your logic made any sense then only countries with standing armies could successfully issue their own currencies, but that's obviously not the case.
Ok, cool. How does that secure the rest of us?
It doesn't, Bitcoin is as safe as the security of the person who holds it. And as someone who had Bitcoin on Mt Gox, this is a moot point to argue.
The point is that the military that the person claimed should be counted in the energy expenditures related to the USD does far, far, far more than "protect the dollar", and even if we all moved to Bitcoin, we'd still have to have the military.