Special Operations Forces in the Year 2K.

[Legbreaker]

Elite forces of all nationalities may have suffered the highest casualty rates of all non-nuked units. Operating well away from any significant support, if they ran into trouble, chances are they'd get wiped out (Just look at Bravo Two Zero in 1991 for an example).
Naturally avoiding these sorts of situations is definately preferable, but after about 5 years of fighting, it's inevitable attrition would have taken a serious toll.
Training replacements may be given a high priority given these units usefulness once aircraft, satellites and other high tech intel options were gone, but my understanding is it takes years to do properly. The units may remain, but the quality of the operators is likely to decrease on average towards the latter half of the war. It's also likely in my opinion that some of the better soldiers from Infantry units, as well as specialists from other areas (signals, engineers, etc) necessary for completion of the assigned tasks would soon find themselves transfered in as replacements. A team of say 10 men may only include 2-3 prewar/fully trained SF troops with the rest filled out with semi-trained (for SF purposes) troops from elsewhere.