The Murtha plan is an attempt to codify a Rumsfeld target of two years at home for every year deployed in combat -- considered a necessary part of recruiting & retention in the out-years. From this target has arisen a myth that there is some military necessity for the 2-to-1 ratio. This is false. A few myths need to be untangled here.
One Democratic staff committee report recently stated:
Army doctrine calls for 2 units to be held in reserve (for rest and training) for every unit deployed. As of today, the Army has only one unit in reserve for every unit deployed—a ratio history shows cannot be sustained for any length of time without serious adverse consequences to the force.
History cannot show that a 1-to-1 ratio is unsustainable, because the current system of a fully modular and rotational "total force" that is only partially at war is entirely new. And in fact, there is nothing necessarily bad about a 1-to-1 ratio, because what it means is that half the force at any given time is not mobilized for deployment.
It is often said that a unit needs one year back home for training for every year it spends abroad. This is false. What Army doctrine calls for in terms of training as a unit is a period of several weeks meant to integrate new recruits (who have already undergone basic training) and get the whole unit used to working together. The rest of the "rest and training" period is best understood as peacetime activity.
Another common myth is that because many units are reporting at low levels of readiness, they are not fully combat capable. This ignores two things.
First, because there is no reason to waste resources rotating tanks and artillery pieces that are largely fungible, units leave much of their equipment behind in Iraq and Afghanistan for incoming forces to fall upon when they get there. It is by design, then, that the units report "not ready" when they rotate back to the United States. As one Marine officer explained to me, what happens during the peacetime "rest and training" period is that units pool their resources so that they can train effectively with the kinds of equipment they will find when they arrive in theater.
Second, peacetime units are not meeting their targets during the rest period because wartime has pushed those targets sky-high—and they reflect the military's judgment of what they would ideally want every unit in a uniform force to have for every possible environment and contingency. But as Joint Chiefs Chairman Peter Pace said in recent Senate testimony, there are 40,000 armored vehicles of all kinds in Iraq that didn't even exist 5 years ago. To lament that the force had higher readiness five years ago than today ignores the fact that both the metrics and the inventories of equipment are astronomically higher now than they were then. And units reporting "not ready" because they don't have the latest equipment they ideally want can still draw on huge stockpiles of older equipment that is almost as good as the new. It may not be as precise, it may be messier, you may have to use more firepower -- but you will still have victory.
As articulated in the the 2006 Quadrennial Defense Review Report, our planning construct now calls for being able to fight an entire conventional campaign in addition to our current commitments in Iraq and Afghanistan. Such a campaign night not be able to do regime change, but it would be able to secure a decisive victory. And rest assured the force is there if we need it. What the military has to worry about is recruiting and retention in the out-years, and the plan to increase the size of the active force by 2 whole divisions in the next several years substantially relieves that pressure now.