[§ 121. Forms of Neutrality and of Neutralization]
The first form of neutrality is what was formerly known as perfect neutrality, in distinction from imperfect neutrality, which allowed a state to give to one of the belligerents such aid as it might have promised by treaty entered into before and without reference to the war. At the present time the only neutrality that is recognized is perfect, i.e. an entire absence of participation in the war. A second form of neutrality is commonly known as armed neutrality. This implies the existence of an understanding, on the part of some of the states not parties to the contest, in accordance with which they will resist by force certain acts which a belligerent may claim the right to perform. The armed neutralities of Feb. 28, 1780, and of Dec. 16, 1800, defended the principle of "free ships, free goods."[390]
Neutralization is an act by which, through a conventional agreement, the subject of the act is deprived of belligerent capacity to a specified extent. Neutralization may apply in various ways.
(1) Neutralized states are bound to refrain from offensive hostilities, and in consequence cannot make agreements which may demand such action. Thus it was recognized that Belgium itself, a neutralized state, could not guarantee the neutrality of Luxemburg in the Treaty of London, in 1867. Belgium is, however, a party to the Treaty of Berlin of 1885, agreeing to respect the neutrality of the Congo State. This agreement "to respect" does not carry with it the obligation to defend the neutrality of the Congo State.
The important instances of neutralization are those agreed upon by European powers. By the declaration signed at Vienna, March 20, 1815, the powers (Austria, France, Great Britain, Prussia, and Russia) "acknowledged that the general interest demands that the Helvetic States should enjoy the benefits of perpetual neutrality," and declared "that as soon as the Helvetic Diet should accede to the stipulations" prescribed, her neutrality should be guaranteed.[391] The Swiss Confederation acceded on the 27th of May, 1815, and the guaranteeing powers gave their acknowledgment on the 20th of November, 1815.[392] The powers also guaranteed the neutrality of a part of Savoy at the same time. The neutralization of Belgium is provided for by Article VII. of the Treaty of London, of Nov. 15, 1831, "Belgium, within the limits specified in Articles I., II., and IV., shall form an independent and perpetually Neutral State. It shall be bound to observe such Neutrality towards all other States."[393]
(2) A portion of a state may be the subject of an act of neutralization, as in the case of the islands of Corfu and Paxo by the Treaty of London, of March 29, 1864. By Article II., "The Courts of Great Britain, France, and Russia, in their character of Guaranteeing Powers of Greece declare, with the assent of the Courts of Austria and Prussia, that the Islands of Corfu and Paxo, as well as their Dependencies, shall, after their Union to the Hellenic Kingdom, enjoy the advantages of perpetual Neutrality. His Majesty the King of the Hellenes engages, on his part, to maintain such Neutrality."[394]
(3) The neutralization of certain routes of commerce has often been the subject of convention. The United States guaranteed the "perfect neutrality"[395] of the means of trans-isthmian transit when the State of New Granada controlled the Isthmus of Panama in 1846. By the Treaty of 1867 with Nicaragua the United States guarantees "the neutrality and innocent use" of routes of communication across the state of Nicaragua.[396] The Nine Powers by the Convention of Constantinople, of Oct. 29, 1888, Great Britain making certain reservations, agree, by a conventional act upon "a definite system destined to guarantee at all times, and for all the powers, the free use of the Suez Maritime Canal."[397] Full provisions for the maintenance of the neutrality of the canal were adopted at this time also.
(4) The Geneva Convention of 1864 neutralized persons and things employed in the amelioration of the condition of the sick and wounded in the time of war.[398] At the present time hospital ships properly certified and designated by flags and by bands of color on the outside are neutralized by general practice.[399]
[§ 122. History]
Neutrality as now understood is of recent growth. In early times, and in general throughout the Middle Ages, the fear of retaliation alone deterred states from hostile action against belligerent states with which they were formally at peace. A belligerent in the prosecution of war might disregard the territorial, personal, or property rights in a neutral state without violation of the principles of public law then accepted.