This is the most favourable hypothesis.  But it is at least conceivable that a Nationalist Government, whether actuated by a laudable desire to hurry on Irish industrial development, or influenced by the tradition of animosity which still plays so strong a part in Nationalist politics, may refuse to enter upon the policy of Imperial preference.  It might even be tempted by various considerations to give a preference to the United States or to Germany.  Germany is a large importer of foodstuffs.  The establishment of a British tariff may prove a serious blow to her manufacturing interests.  A trade agreement with Ireland might be a very useful temporary business expedient from the German point of view.  Incidentally a large increase of German merchant shipping in Irish harbours might, in the case of possible hostilities, be of no little service in providing commerce destroyers with a most convenient excuse for being in the most favourable area for their operations.  Any fiscal excursions of that sort would inevitably be visited upon Ireland by severe economic reprisals of one kind or another on the part of Great Britain, from which Ireland would receive permanent injury far outweighing any temporary advantage which might be secured from foreign countries.

In other words, Ireland under Home Rule would be in almost every respect thrust back into her eighteenth century position of “least favoured Colony.”  She would, at the best, be handicapped in the British market in respect of those products by which she could profit most, and in those which she is less fitted to produce would have to compete with the virgin soil and competitive energy and organisation of the great Dominions.  At the worst, her fiscal policy might invite reprisals and make her “least favoured” not only by her circumstances but by the intention of those who would frame the British tariff.  It is true that the British Government would no longer dream of directly interdicting Irish exports.  But in that respect modern organised capital has an influence to promote or kill almost as great as that of governments in former times.  And the influence of British capital, under such circumstances, would certainly not tend to be directed towards the economic development of Ireland.

But the use of the customs tariff is by no means the only great instrument of a national economic policy.  To promote the flow of trade in national channels, to secure the fullest development of the national territory and resources, the removal of natural internal barriers is often even more important than the setting up of artificial external barriers.  Statesmen who have had to face the task of giving strength and solidity to weak political unions have always aimed at the development of internal communications.  Washington’s first concern after the success of the American War of Independence was to endeavour to create a system of internal river and canal navigation in order to help to bind the loosely allied States