tever the number, a commander on a
particular echelon occupies the position of an immediate subordinate
to a commander on the next higher echelon, and that of an immediate
superior with relation to a commander on the next lower echelon.
Within these confines, authority is exercised and accomplishment
exacted, both to the extent calculated to ensure unity of effort.

There may frequently be found two or more commanders occupying
coordinate positions on the same echelon, all with the same immediate
superior, and all charged with loyalty to him and to each other in the
attainment of a common objective. In no case, however, will a
commander be directly answerable to more than one immediate superior
for the performance of the same duty. Thus is fulfilled the
requirement that the command, although relatively narrower in scope as
the scale is descended, be reposed in a single head.

The experience gained and the knowledge acquired during early service
on the lower echelons provide a basis for later expansion of
viewpoint, a better understanding of the position occupied by the
subordinate and of the obligations of higher command, including its
dependence on subordinates. As the echelons of command are ascended,
the details involved become more and more numerous, because of the
increased scope of the problems. On the higher echelons, therefore,
staff assistance is provided so that the commander may be left free to
consider matters in their major aspects. The staff of a commander is
not, however, a part of the chain of command; its members, as such,
exercise no independent authority.

A chain of command is not created by the subdivision of the officer
corps into grades on a basis of relative rank. Such subdivision is for
the purpose of classification from the standpoint of potential
competency and capacity for responsibility, and carries no authority
to command by virtue of rank alone. Organization, systematized
connection for a specific purpose, is first necessary.

The armed forces, during peace, are usually subdivided into permanent
major organizations for the purpose of attaining and maintaining
readiness for action. From the several grades of the officer corps, a
permanent chain of command is instituted by the process of organization,
the supreme command being reposed in a commander-in-chief. The basis of
the permanent organization is that chosen as best suited to attain and
maintain readiness. Its choice requires consid