What are these aircraft at AMARG? Why are they dismantled this way? At the AMARG boneyard (Tucson desert, Arizona), there are tons of aircraft, but a limited number of models are dismantled according a special way: wings or tail or both separated from the fuselage:


Image from Google Maps


Source, reframed

I doubt all tails will suddenly be used as spare parts...

What are those military aircraft? why are they systematically dismantled this way?

(Not sure the question is on topic.)
Some B-52s and other aircraft were put out of commission as part of the START treaties.  They were dismantled in such a way that the Russians could verify this with satellite reconnaissance, just as in the photo above.