_The Immediate Effects of the Outbreak of War_
Before any actual hostilities have taken place, each belligerent acquires, _ipso facto_, certain new rights over persons and property belonging to the other, which happen to be at the time within its power, e.g. the right, much softened in modern practice, and specifically dealt with in The Hague Convention, No. vi. of 1907, of capturing enemy merchant vessels so situated.
The following letter deals with the permissible treatment of enemy persons so situated; and was suggested by a question asked in the House of Commons on February 25, 1909, by Mr. Arnold-Forster: viz. "What would be the _status_ of officers and men of the regular Army of a hostile belligerent Power, found within the limits of the United Kingdom after an act or declaration of war; and would such persons be liable to be treated as prisoners of war, or would they be despatched under the protection of the Government to join the forces of the enemy?" The general effect of the Attorney-General's reply may be gathered from the quotations from it made in the letter.
The topic was again touched upon on March 3, in a question put by Captain Faber, to which Mr. Haldane replied.
Sir,--The question raised last night by Mr. Arnold-Forster is one which calls for more careful consideration than it appears yet to have received. International law has in modern times spoken with no very certain voice as to the permissible treatment of alien enemies found within the territory of a belligerent at the outbreak of war.
There is, however, little doubt that such persons, although now more usually allowed to remain, during good behaviour, may be expelled, and, if necessary, wholesale, as were Germans from France in 1870. But may such persons be, for good reasons, arrested, or otherwise prevented from leaving the country, as Germans were prevented from leaving France in the earlier days of the Franco-Prussian War? Grotius speaks with approval of such a step being taken, "ad minuendas hostium vires." Bynkershoek, more than a century later, recognises the right of thus acting, "though it is rarely exercised." So the Supreme Court of the United States in _Brown v. United States_ (1814). So Chancellor Kent (1826), and Mr. Manning (1889) is explicit that the arrest in question is lawful, and that "the individuals are prisoners of war."