for importation; but
in normal times domestic sources can supply a considerable fraction of
the demand only at high cost and with the aid of a protective tariff.

No attempt will be made here to present the detailed figures on which
the above generalizations are based. In view of the present disturbed
conditions of production and consumption, any judgment as to future
demands or available surplus must take into account several factors
which cannot be accurately measured,--such as financial control in
foreign countries, possible tariffs, and foreign competition. For this
reason the above statement should be regarded as only tentative, though
it is the result of a rather exhaustive study of conditions in relation
to the world control of shipping. The classes named overlap to some
extent, and it is to be expected that some of the commodities placed in
one class may in the near future be transferred to another.

In terms of value, the United States has a potential export surplus of
minerals about twice as large as that of all the rest of the world put
together. Countries which were neutral during the war have the remaining
export surplus. Great Britain, France, and Italy have net import
requirements considerably in excess of their exports. Germany has almost
as large a deficit of minerals as the United States has a surplus.

From the above facts it is clear that, in any scheme of international
control or cooperation, the United States would have by far the heaviest
stake, and perhaps the most to lose by restriction. It seems equally
clear that the preponderance of exportable surplus of minerals over
necessary imports justifies the United States in taking a broad and
liberal view of the importation of needed minerals. The war-time
necessity of making our country as nearly self-sustaining as possible
does not seem to obtain in peace times. To carry that principle to an
extreme means not only the expensive use of low-grade domestic supplies,
but the elimination of the imports which are so necessary to balance our
export trade.

These facts also raise the question as to how far the United States is
justified in exploiting the rest of the world to add to its already
great preponderance of control,--as, for instance, in copper. Any
further aggrandizement of our position in regard to such minerals may be
directly at the expense of neighbors who are already far less well
supplied than ourselves, and is to be justified only on t