One of the myths of World War II is that, unlike in Europe, unity of command was lacking in the Pacific. The argument goes that the Southwest Pacific had one commander, General Douglas MacArthur, and the Pacific Ocean areas had another, Admiral Chester Nimitz. MacArthur often commented that the Pacific Ocean areas drained resources for little gain that he could have put to far better use. In his memoirs, he railed against the command structure: "Of all the faulty decisions of war perhaps the most unexplainable one was the failure to unify the command in the Pacific.... [It] cannot be defended in logic, in theory, or in common sense.... It resulted in divided effort, the waste, diffusion, and duplication of force, and the consequent extension of the war, with added casualties and cost." (1)
For its part, the Navy believed that the Pacific war was "a naval problem." Admiral Ernest King, Chief of Naval Operations, insisted that "the entire Pacific Ocean should constitute a single theater with a unified Naval command headed by Nimitz." (2) Because MacArthur and Nimitz were so powerful, and because their champions in Washington were so entrenched, however, unity could not be achieved. As a result, a fundamental principle of war was violated, and the result was inefficiency, confusion, waste, and an "ad hoc" and "piecemeal strategy." (3) Another historian is even more critical, arguing that the U.S. effort in the Pacific was "hamstrung" because of the inability to appoint a single theater commander. The result was "a wasteful allocation of resources, a dispersion of effort, and a consistent failure to pursue the most effective and economical strategy against the Japanese." The compromise of appointing two commanders for two different theaters was "grotesque." (4) In truth, however, a basic assumption of the above argument is false. There was no unified command in Europe, so the ideal to which the critics of the Pacific war allude never existed.
Defining Unity of Command
First, a word about the term unity of command is in order. Principles of war, in one form or another, have been claimed since Sun Tzu wrote over 2,000 years ago. The first modern effort to enumerate such principles was by a British officer, then-Captain J.F.C. Fuller, who published them in 1916. These principles were soon enshrined in British Field Service Regulations, and in 1921 were adopted with minor revisions by the U.S. Army. These early doctrinal writings referred to a principle of "cooperation" that allowed diverse fighting forces to work efficiently toward success. (5) By 1931, the U.S. Army had substituted the term unity of command for this idea, stating authoritatively: "It is a well-established principle that there shall be only one commander for each unit, and one commander in each zone of action, who shall be responsible for everything within his unit or within his zone of action." (6) This principle was not, however, established in a joint environment. Theater commanders were not yet common in American military operations; rather, Army and Navy commanders were still expected simply to "cooperate" when circumstances dictated. This would lead to problems as late as 1941, when the Services could not agree on a single commander for the Caribbean.
The Caribbean was a crucial theater for the United States because it guarded the Panama Canal, vital to hemisphere defenses. Yet when the Army appointed Lieutenant General Daniel Van Voorhis as commander of the Caribbean Defense Command, it quickly discovered that the Navy had other ideas. Whenever Van Voorhis attempted to exert the authority given him by the President over the naval forces in the theater, local admirals replied tartly that "he was not in their chain of command." (7)
Pearl Harbor changed things. In October 1942, U.S. planners preparing for the Casablanca Conference issued a definition to guide Allied leaders regarding future joint and combined commands:
Unified command is the control, exercised by a designated commander, over a force integrated from combined and joint forces allocated to him for the accomplishment of a mission or task. …