Of course you can. But x86 machine code doesn't have Monads just because Haskelll can be compiled to it. In both cases, the concepts have to be broken up to be implemented, as they are not meaningful at that level.
Can you please explain. Which REST concept cannot be implemented? I think the problems that REST/SOAP solve,is that the "levels" that you speak about, have already been implemented by someone else. I am talking of serialization, transport level details (e.g. SOAP over JMS) etc. If even transport level abstraction has been taken care of by the implementers, then which concept do you think, cannot be implemented.