sorry, Chief. Went off on a "limiting factors" tangent
Technically, our view of grand strategy is based upon the Clausewitzian system, which has been in place for 200 years, at least for the Army. This is what new-age Pentagonese speakers refer to as "Second Generation Warfare".
The Marine Corps uses "Third Generation Warfare", or what is more commonly called maneuver conflict.
But doctrine aside, the purpose of the infantryman has always been the same- to assault and hold a landbased objective. Barring weapons and technology, very little has changed in the way of maneuvers and tactics