Complication

One thing I neglected to consider when I figured we could get down to one year tours for Army forces with one year at home this year is that some Army brigades still need to transition to the new organization. This keeps them out of the rotation pool while they reorganize. Lieutenant General Carter Ham explains:

If it were that simple, if it were directly tied only to the number of brigade combat teams, then we'd be able to answer pretty definitively at this level deployment length would be x. But there are so many other factors to include, other global demands that are existent that we have -- that we have for our forces; the need for reset, reconstitution; some of the units will still have to be -- are still undergoing transformation. So there's -- and, of course, the Army and the Marine Corps are both growing. So all of those factors make it too uncertain to be able to pin a precise number to say if we get to X number of brigades, then we'll be able to go to this length of deployment.

Back in 2005, when the Army was reorganizing ("undergoing transformation") the first group of brigades, the National Guard picked up the slack. I'd guess the Guard could do the same again if needed, but that call is beyond the Army to assume.