Industrial preparation for war was guided by the principle of priority. This is an old principle, but it began to be applied in unheard-of ways. When an army is to be moved all means of transport in sight are commandeered. When an army is to be fed, civilians protest in vain against the seizure of stores. These practices were always features in the history of warfare. A novel factor in priority as applied during the present war was the breadth of its scope. "When the whole industry of a nation is mobilized behind the fighting line, it is not merely finished munitions that must be given priority in transportation, but also the materials and fuel for further munitions production. The food supply of the industrial population, as well as that of the army, has a claim to priority. So also have clothing supplies, lumber for housing, and whatever else is essential to working efficiency. In production it would be impossible to fix definite limits upon the application of the priority principle. We can not much longer permit the free flotation of the securities of foreign enterprises, nor even of the less essential domestic enterprises, so long as national loans or issues designed to finance railways or industrial enterprises of prime necessity are to be floated. Modern warfare, in involving the whole national life, has made inevitable a control of business practically coextensive with the economic system. "The application of the priority principle to transportation and production is quite in accord with plain common sense. It is none the less revolutionary in its social economic implications. What it means is that necessities shall have right of way. If we have excess productive capacity, the unessentials and luxuries may be provided, but not otherwise. And necessities are definable in terms that take account only of physical requirements. There is no room in the definition for class distinction. A new country house may seem a matter of necessity to the man of fortune, but he will persuade no priority board to permit shipment of building materials while cars are needed for coal or wheat. Nor will he persuade them to let him have lumber that could be used for ships or workingmen's camps, or labor that could be employed to advantage in production for more clearly national and democratic needs." WAR SUPPLIES The United States, following the experience of other belligerents, adopted the policy of decentralization in the production of war supplies. A plan was worked out under which the small and large manufacturer were given equal opportunity to obtain war business: