The article to which you linked has a wide array of details wrong and displays a lack of understanding of how forces are deployed into a theater of combat. That said, the bottom line point--the availability of combat brigades and the need (under current policy) to rotate them--is a good one. I would caution anyone from taking much else as correct.
Huh. Thanks for the heads up, and if you have a minute to explain a bit, it would be much appreciated.
re: 2
A few points:
While the ratios vary by situation, and I do not know exactly what they are in Iraq, it is normal that combat units have a big support tail. Thus, I imagine that a substantial number of the 150,000 troops in Iraq are not the ccombat units on which the author focuses. This is inherent in the way the military is organized. Here is a list of units, including the over 20,000 Marines that are ignored by the article.
As you can see, a lot of the forces in the theater of operations are not combat units. Further, combat brigades operating independently are organized with their own combat support units (maintenance, medical, engineers, etc.)
The article does not count as combat units units traditionally included in the combat arms, such as field artillery and combat aviation, also ignored are combat engineers and military police, which are considered combat support, but which are certainly good at providing security.
An important point--not discussed in the article and on which reasonable people disagree--is the extent to which in a situation such as we face it makes a huge difference that a unit is a combat brigade. Combat engineers and military police are probably better trained and equipped to provide security than armored units. As I understand it, the artillery units in Iraq have done a lot of traditionally-infantry missions (although almost certainly not the hardest or most complex).
Finally, a lot of the most important work in Iraq is being done by non-combat units, such as civil affairs, engineers, medical, transportation etc. which work on civil and infrastructure development. Ultimately, one would hope that as the security situation improves, those support units would come to predominate.
You seem to be suggesting that there are more utilizable troops than Kaplan makes out, which suggests that there could be more boots on the ground in Iraq. Is that accurate? Or, is Kaplan wrong about the # of utilizable troops, but nonetheless somehow right that there aren't any more troops to be had?
re: 4
His point about there not being more troops is inacurate in the details for the reasons I describe above, and particularly because he seems to be unaware of the fact that most of the troops in a theater of combat are not "combat" troops as he discusses them. His point is not a bad one in the general sense that it is important to realize that it would be hard simultaneously to fight another war (or significantly to increase the number of troops fighting in Iraq) because under the current rotation system, for every unit in theater, there are a couple in the States recovering and getting ready to re-deploy. Of course, it would be easy to get more troops on the ground if the rotation system were modified. Further, and I do not know nearly enough about the military situation in Iraq to guess how things are, it may be that the limiting factor on the size of the force is the number of combat support and combat service support units (civil affairs, engineers, military police, transportation, medical, etc.) that are available, not combat forces. I do not know this to be true, but given that a lot of the military's support units come from the reserve components, it is certainly possible. Ultimately, it is as much a question of the mix of boots on the ground as the number of boots on the ground.