had become so intense that
President Wilson (August 18, 1914) was moved to caution his countrymen
against falling into angry disputes. "Every man," he said, "who really
loves America will act and speak in the true spirit of neutrality which
is the spirit of impartiality and fairness and friendliness to all
concerned.... We must be impartial in thought as well as in action, must
put a curb upon our sentiments as well as upon every transaction that
might be construed as a preference of one party to the struggle before
another."

=The Clash over American Trade.=--As in the time of the Napoleonic wars,
the conflict in Europe raised fundamental questions respecting rights of
Americans trading with countries at peace as well as those at war. On
this point there existed on August 1, 1914, a fairly definite body of
principles by which nations were bound. Among them the following were of
vital significance. In the first place, it was recognized that an enemy
merchant ship caught on the high seas was a legitimate prize of war
which might be seized and confiscated. In the second place, it was
agreed that "contraband of war" found on an enemy or neutral ship was a
lawful prize; any ship suspected of carrying it was liable to search and
if caught with forbidden goods was subject to seizure. In the third
place, international law prescribed that a peaceful merchant ship,
whether belonging to an enemy or to a neutral country, should not be
destroyed or sunk without provision for the safety of crew and
passengers. In the fourth place, it was understood that a belligerent
had the right, if it could, to blockade the ports of an enemy and
prevent the ingress and egress of all ships; but such a blockade, to be
lawful, had to be effective.

These general principles left undetermined two important matters: "What
is an effective blockade?" and "What is contraband of war?" The task of
answering these questions fell to Great Britain as mistress of the seas.
Although the German submarines made it impossible for her battleships to
maintain a continuous patrol of the waters in front of blockaded ports,
she declared the blockade to be none the less "effective" because her
navy was supreme. As to contraband of war Great Britain put such a broad
interpretation upon the term as to include nearly every important
article of commerce. Early in 1915 she declared even cargoes of grain
and flour to be contraband, defending the action on the ground that the