MARINE CORPS OPERATIONS Marine Corps Doctrinal Publication (MCDP) 1-0, Marine Corps Operations, provided a bridge between the maneuver warfare philosophy articulated in our first nine MCDPs and the tactics, techniques, and procedures contained in our warfighting and reference publications. It focused on describing the role of the Marine Corps component in providing, sustaining, and deploying Marine Corps Forces at the operational level of war and on how the largest of our Marine air-ground task forces (MAGTFs), the Marine expeditionary force, conducted operations at the tactical level. Developed just prior to, and published shortly after, the momentous events of 11 September 2001, the original edition reflected the language and operational constructs prevalent within joint doctrine at that time. Key among them were the notions of "war" versus "military operations other than war," as well as the unstated, but embedded, belief that the ability to defeat a conventional adversary granted the ability to succeed against "lesser" foes. Since then, Marines have successfully conducted a wide variety of expeditionary missions. These missions have included the projection of a landing force from amphibious ships in the Indian Ocean more than 400 miles inland into Afghanistan; a mechanized attack from Kuwait to Baghdad, followed by prolonged counterinsurgency operations to pacify major portions of Iraq; and numerous foreign humanitarian assistance and crisis response operations worldwide. Critical to the success of these missions was the role played by forward-postured, sea-based forces and resources that were employed singly or with others and surged from dispersed global locations. Crisis response has long been the stock-in-trade of--indeed the rationale for--forward-deployed, sea-based Marines; however, Marines have also become a force of choice for various engagement activities employed by the geographic combatant commanders to build partnerships and proactively shape what is now called the operational environment. The diversity of operations, the expanded application of Marine Corps capabilities, and the changing lexicon all illustrate how our collective American understanding of the security era, our national strategy, our organizations, and our employment of military power have evolved during nearly ten years of conflict. Accordingly, this edition, which supersedes its predecessor, reflects that evolution. This publication records changes to Marine Corps organization and force posture. It discusses the use of smaller MAGTFs and other, nonstandard formations that are increasingly employed with our joint and multinational partners--especially those in the Navy and special operations forces--and how we plan, execute, and assess our expanded activities across the range of military operations. It provides concise descriptions of the various operations Marines may conduct and elaborates on the various tactical operations that Marine Corps commanders may integrate, in varying degrees, to successfully accomplish assigned missions. Marine Corps commanders and staffs at all levels should read, study, and be thoroughly conversant with the content of MCDP 1-0. The notion that "words matter," is embedded throughout this publication, which defines key terms to ensure Marines speak a common operational language. Inasmuch as MCDP 1-0 illustrates how the flexibility and rapid deployability of our task organized, combined arms forces apply across the range of military operations, joint and multinational force commanders and their staffs can also use this publication.