whoa...pop quiz ...good question ! it's the only navy\Marine ribbon with no medal attached, but darned if I know why.
In fact, you could have been awarded the Purple Heart and not get the CAR.
And at one time (may still be true today) it's only for Col & below. (or Capt & below in Navy)
The reason is that if there is no medal then when in Dress Blue A’s you would wear medals on the left and ribbons w/o medals on the right...thus the CAR would stand out!
Now another question....on a CAR what criteria rates multiple awards (stars)....I was overseas (Iraq) and was involved in many firefights, RPG attacks and two IED attacks....but yet I only rated one CAR? Interesting, the only thing I can figure is had I been deployed more than once maybe I would have rated it?!