But there are limits to the extent to which belligerents may interfere with the inter course of neutral states with the enemy. These limits mark what may be called the rights of neutrals. For a detailed state ment of the rights and duties of belligerents and neutrals, see NEUTRALITY.
It has been suggested within recent years that certain rules of international law need to be modified when applied to the states of the American Continent. These modified rules may be said to constitute American In ternational Law. On January 4,' 1909, the First Pan American Scientific Congress held "that on this Continent there are problems sui generic or of a distinctly American char acter and that the states of this hemisphere, by means of agreements more or less general, have regulated matters which are of sole concern to them, or which, if of universal interest, have not yet been susceptible ot universal agreement—thus incorporating in international law principles of American origin." The codification of international law has been much discussed within recent years. The idea was first suggested by Bentham, 'whose fondness for ideal codes, not based upon the facts of international and national life, is well known. In 1863, at the request of President Lincoln, a code of the laws of war was drawn up by Francis Lieber for the use of the Federal armies, a large por tion of which is embodied in the Convention concerning the Laws and Customs of War on Land, adopted by the Second Hague Con ference. More elaborate and comprehensive codes are those of Bluntschli, published in 1868, of David Dudley Field, published in 1872, and of .Pasquale Fiore, published in 1890. The conventions of the two Hague Conferences, together with 111e Declaration of London (q. v.), represent an attempt to codify international law, upon certain spe cific heads. How far codification can be suc cessfully carried has been much discussed.
Certain parts of international law are still in an undeveloped state, and it might per haps be unwise to define rules which may soon be outgrown. Besides, it is clear, from the obstinate position taken by the powers at the Hague Conferences, that they are not yet ready for an agreement which will be in conflict with principles which they have long considered essential to their welfare and prosperity. While it is generally rec ognized by nations that the principles of in ternational law should, in point of justice and morality, come up to the standard of the municipal law of individual states, at the same time the conflicting commercial in terests of the Great Powers, and the increas ingly intense national spirit manifested by them, make it difficult for them to reach an agreement upon any subject in which na tional interests are intimately involved. For a critical bibliography of the principal writers on international law, see 1 Opp. 83– 103 ; also Hershey, Essentials of Int. Pub. Law 86-91.
International law is said by Sir F. Pollock to be a true branch of law notwithstanding all that may be said about its want of sover eign power and a tribunal. Its doctrines are founded on legal, not simply on ethical, ideas. They are not merely prevalent opin ions as to what is really right and proper, but something as closely analogous to civil laws as the nature of the case will admit. They have been discussed by the methods appropriate to jurisprudence and not by those of moral philosophy. They appeal not to the general feelings of moral rightness, but to precedents, to treaties and to the opin ion of specialists. They assume the exist ence among statesmen and publicists of a sense of legal as distinguished from moral obligation in the affairs of nations. Oxford Lectures 18. See also Westlake, Intern. Law.