Doctrine is developed to serve as a template for military operations. The effect of doctrine is to influence how military Services and members think about, and fight, wars. In the U.S. Marine Corps, two significant doctrinal publications, the Tentative Landing Operations Manual (1934) and Warfighting (1989), were written to change Service culture in a manner that reflected external and internal pressures on the Corps. This article examines these two publications against existing definitions of effective doctrine, and considers the role doctrine played in shaping Service culture in the Marine Corps using the landing manual and Warfighting as examples.