And how exactly does he plan to do that?

Short of reinstating involuntary conscription, I mean:

WASHINGTON, Dec. 19 — President Bush said Tuesday that the United States should expand the size of its armed forces, acknowledging that the military had been strained by the wars in Iraq and Afghanistan and would need to grow to cope with what he suggested would be a long battle against Islamic extremism.

“I’m inclined to believe it’s important and necessary to do,” Mr. Bush said. He said this was an “accurate reflection that this ideological war we’re in is going to last for a while, and that we’re going to need a military that’s capable of being able to sustain our efforts and help us achieve peace.”

More.