Upon his return to the U.S., Upton proposed a number of radical reforms, including abandoning the citizen-soldier model and relying on professional soldiers, reducing civilian interference in military affairs, and abandoning the emphasis on the constabulary operations in favor of preparing for a conflict with a potential foreign enemy.There's much more here.
I view Upton's thinking as the next logical stage in the Grant-Sherman-Schofield professionalization paradigm and the current culture of the officer corps as embodying its ultimate, corrupted, hyperreal expression.