Knowl­edge­able observers have long sug­gest­ed that this was the case, but an offi­cial Con­gres­sion­al Bud­get Office analy­sis agrees that the esca­la­tion in Iraq will be larg­er than offi­cials have claimed. The issue is that when the Pres­i­dent talks about 21,500 extra com­bat troops, you have to send addi­tion­al sup­port units. Those extra com­bat units need truck dri­vers, mil­i­tary police, head­quar­ters staff, com­mu­ni­ca­tions experts, engi­neers, intel­li­gence offi­cers, and med­ical assis­tance. To sup­port the com­bat units being deployed, you have to send addi­tion­al non-com­bat units (which will still encounter dan­ger­ous con­di­tions, naturally).

The non­par­ti­san CBO con­sid­ered two scenarios:

In one sce­nario, CBO assumed that addi­tion­al sup­port troops would be deployed in the same pro­por­tion to com­bat troops that cur­rent­ly exists in Iraq. That approach would require about 28,000 sup­port troops in addi­tion to the 20,000 com­bat troops—a total of 48,000. CBO also presents an alter­na­tive sce­nario that would include a small­er num­ber of sup­port personnel—about 3,000 per com­bat brigade—totaling about 15,000 sup­port per­son­nel and bring­ing the total addi­tion­al forces to about 35,000.

For com­par­i­son, there are about 140,000 troops cur­rent­ly deployed to Iraq, so we are talk­ing about a 30% increase. Those addi­tion­al forces will be deployed into the most dan­ger­ous parts of Iraq, giv­ing them much high­er casu­al­ty rates, one pre­sumes. What we will get in exchange for that sac­ri­fice is not at all clear.