>>458 (OP)
That country is an island nation. It makes much more sense to reduce trash output in that setting than it does on a large landmass. We actually are not at any risk of "filling up the landfills" any time soon. The world is a big place. Additionally, in the US, disposable diapers account of only about 1% of the total landfill volume. Compare that with paper products at around 50% (If I remember correctly) and it is clear where we will be focusing our efforts even if running out of space were a problem. Yard waste also takes up a much larger volume in the US.
That being said, it never hurts to find a way to recycle something. With diapers, the big problem is finding a way to separate the pee/poop from the SAP without destroying the diaper in the process. One idea would be to make the diaper "shell" a much sturdier structure and the absorbent part would be just a simple pouch or liner you insert into it. This would reduce the amount of plastic being used, and also make it easier to separate the desired components from everything else. It wouldn't be nearly as big of a problem from an engineering point of view if you could just take the absorbent insert and throw it into a grinder and go from there. You now only have up to 5 materials to sort: The SAP, the filler/pulp, the material used to contain the SAP and filler, pee, and poop. Compare that to all of that plus the plastic backing, fabric backing, elastics, glues, leak guards, tapes, and the velcro landing strip, and you can see how the job gets a lot easier.
Another idea would be to use something called a "super critical water oxidizer". These are in no way ready for wide spread use, but theoretically are a wonderful option for waste management, especially if you are trying to make a closed loop system (like a space colony or one on the moon or another planet). Basically, the idea is to heat and pressurize water just right so that it reaches its "supercritical point" At this particular temperature and pressure, water exists simultaneously in a liquid and a gaseous state. You then inject whatever waste you want to get rid of into the reaction chamber with the supercritical water along with a jet of pure oxygen. The resulting reaction will effectively disintegrate any organic compounds and reduce them to there basic molecular components. Anything not organic comes out as slag. In a closed loop system, the output organics are then used to feed crops, and synthesize all sorts of plastics and other products. The great part is that this works equally well as a trash management system and as a human waste treatment system.
Last I heard, these things are far from actually working as well as I just made them sound in practice. Currently they are only used for niche applications.