I am really not sure this is true. Here is a quote from Zen Mind, Beginner's Mind:
> If you are concentrated on your breathing you will forget your- self, and if you forget yourself you will be concentrated on your breathing. I do not know which is first. So actually there is no need to try too hard to be concentrated on your breath- ing. Just do as much as you can. If you continue this practice, eventually you will experience the true existence which comes from emptiness.
So yes, you induce meditation by choosing (in your mind) to watch your breath but that's no different from choosing to play a game. Furthermore you're merely watching your breath, not controlling it. So it could be argued that the concentration arises secondary like it does when you focus on a game.
But then again arguing takes places on a dualistic level, so what's the point (in this specific case)?