the other hand, was
absolutely without legal justification. It did not fulfill the
requirements of a valid blockade, because it cut off only a very small
percentage of British commerce, and the first requirement of a blockade
is that it must be effective. The decree was aimed directly at enemy
merchant vessels and indirectly at the ships of neutrals. It utterly
ignored the well-recognized right of neutral passengers to travel on
merchant vessels of belligerents. The second decree announcing
unrestricted submarine warfare after February 1, 1917, was directed
against neutral as well as enemy ships. It undertook to exclude all
neutral ships from a wide zone extending far out on the high seas,
irrespective of their mission or the character of their cargo. It was
an utter defiance of all law.

The citizens of neutral countries have always had the right to travel
on the merchant vessels of belligerents, subject, of course, to the
risk of capture and detention. The act of the German ambassador in
inserting an advertisement in a New York paper warning Americans not to
take passage on the _Lusitania_, when the President had publicly
asserted that they had a perfect right to travel on belligerent ships,
was an insolent and unparalleled violation of diplomatic usage and
would have justified his instant dismissal. Some action would probably
have been taken by the State Department had not the incident been
overshadowed by the carrying out of the threat and the actual
destruction of the _Lusitania_.

The destruction of enemy prizes at sea is recognized by international
law under exceptional circumstances and subject to certain definite
restrictions, but an unlimited right of destruction even of enemy
merchant vessels had never been claimed by any authority on
international law or by any government prior to the German decree. The
destruction of neutral prizes, though practised by some governments,
has not been so generally acquiesced in, and when resorted to has been
attended by an even more rigid observance of the rules designed to
safeguard human life. Article 48 of the Declaration of London provided
that, "A captured neutral vessel is not to be destroyed by the captor,
but must be taken into such port as is proper in order to determine
there the rights as regards the validity of the capture."
Unfortunately Article 49 largely negatived this statement by leaving
the whole matter to the discretion of the captor. It is as