The defense capability of the United States is so inextricably related to the capability of industry that any program which affects that capability is of direct interest to the Department of Defense. In the event that the metric system should be adopted throughout the United States, both industry and the Department of Defense would be confronted with certain problems. These problems might be classified into three general areas: (1) maintenance of an adequate production base throughout the period of conversion to metric units without restricting the ability of industry to expand production rapidly in the event of mobilization; (2) replacement of a huge inventory of repair parts at minimum expense and without impairment of logistics support; and (3) training of personnel to use and maintain equipment involving metric units of weights and measures. If the defense establishment is to maintain a high level of preparedness, a program to adopt the metric system of necessity must take into consideration this close relationship between the defense establishment and industry. The defense establishment, in itself, is not in a position to initiate or veto initiation of the metric system. It must adapt to decisions made in the interests of the national economy as a whole. Whatever merits or demerits attach to adoption of the metric system generally are also pertinent to the Department of Defense. However, once the metric system is adopted in any particular segment of industry, the Department of Defense can serve as an effective catalytic agent for its wide and expedited adoption. This role stems from the substantial magnitude of defense research, procurement and operations.