This community of operation is so evident that, historically, the advocates of exemption of private property from confiscation in the one case have demanded, or at the least suggested, that blockade as a military measure cannot be instituted against commerce—that it can be resorted to only as against contraband, or where a port is “invested” by land as well as by sea. This was Napoleon’s contention in the Berlin Decree; and it is worthy of grave attention that, under the pressure of momentary expediency, the United States more than once, between 1800 and 1812, advanced the same view. This I have shown in my history of the War of 1812.[120] Had this opinion then prevailed, the grinding blockade of the War of Secession could not have been applied. If we may imagine the United States and the Confederate States parties to a Hague Conference, we can conceive the impassioned advocacy of restricted blockade by the one, and the stubborn refusal of the other. This carries a grave warning to test seeming expediency in retaining or yielding a prescriptive right. There is no moral issue, if my previous argument is correct; unless it be moral, and I think it is, to resort to pecuniary pressure rather than to bloodshed to enforce a belligerent contention. As regards expediency, however, each nation should carefully weigh the effects upon itself, upon its rivals, and upon the general future of the community of states, before abandoning a principle of far-reaching consequence, and in operation often beneficent in restraining or shortening war. It has been urged that conditions have so changed, through the numerous alternatives to sea transport now available, that the former efficacy can no longer be predicted. There might be occasional local suffering, but for communities at large the streams of supply are so many that the particular result of general popular distress will not be attained to any decisive degree. Has this argument really been well weighed? None, of course, will dispute that certain conditions have been much modified, and for the better. Steam not only has increased rapidity of land transit for persons and goods; it has induced the multiplication of roads, and enforced the maintenance of them in good condition. Thanks to such maintenance, we are vastly less at the mercy of the seasons than we once were, and communities now have several lines of communication open where formerly they were dependent upon one. Nevertheless, for obvious reasons of cheapness and of facility, water transport sustains its ascendancy. It may carry somewhat less proportionately than in old times; but, unless we succeed in exploiting the air, water remains, and always must remain, the great medium of transportation. The open sea is a road which needs neither building nor repairs. Compared with its boundless expanse, two lines of rails afford small accommodation—a circumstance which narrowly limits their capacity for freight.