Look to the east, on the morning of the fifth day. I have a feeling that the 4th Infantry and Eomer have something in common, here... just a hunch.
I can like the analogy of Saddam being Saruman... A power of evil who nevertheless is a mere henchman for some greater evil, as yet without a form we can see, though we feel it when it is near.
I am not fully on board with America being Rohan, because I see us as strong, not suffering to rise out of a long slow decay, but perhaps it will work, with the exaggeration known to happen in allegory.
The only place that allegory falls apart is Saruman's overwhelming force against a weaker Rohan. The overwhelming force is clearly ours, though we share none of the goals. We are the battle of Helm's Deep as it should have been perhaps... Taking out the evil before it can become strong.
It is an imperfect allegory, to be sure. They, however, are Orc-Kind, of this there can be no doubt, and there are buttloads more of them where those came from. Actually, it scares me a little that the allegory may be closer to the truth than we yet know.