In consequence of this principle in international law, neutralization is applied in very varied ways according to the very varying conditions of those who have the benefit of it, and altogether in harmony with their wishes. Thus, for example, neutralization when it concerns a territory, consists not only in forbidding any warlike operation in the domain thus rendered inviolate, but involves a similar prohibition with respect to any marching or countermarching of armies, or smaller detachments, even of single officers or soldiers.
A canal or a strait may be so neutralized, on the other hand, that all warlike operations are forbidden in it, but nevertheless it is open for passage through, yet upon condition that no belligerent has a right, in passing through, to land upon the shores of the neutralized region.
This is the kind of neutralization which appears applicable to the Scandinavian seas.
One question which for a long time came up constantly at the congresses of Peace Societies, was the Neutralization of the Suez Canal, until it became at last solved in practice. After tedious negotiations, this burning question was settled by an agreement between England and France in the treaty of October 24, 1887, which was later entered into by the other powers interested and that important channel of communication became at all times inviolate.[24]
Upon the programme of the friends of peace questions have long been mooted respecting the neutralization of Elsass-Lothringen, and of the Balkan States, together with that of the Danube, Bosphorus, Sea of Marmora, Dardanelles, and their European coasts; whereupon should follow the rendering inviolate of Constantinople; as also of the Baltic, and as a result of this, the neutralization of the Scandinavian kingdoms.
In connection with the neutralization of the Sound has arisen the still newer question of the non-German region north of the North Sea Canal, now in course of construction, between the mouth of the Elbe and the naval port of Kiel.
By constituting Elsass-Lothringen into an independent neutral State, a division would be made between France and Germany, and these great powers would be separated by a huge wall of neutral States which would also narrow in an essential degree the European battle-field.
The same result is hoped for from a confederacy of neutral States on the Balkan, with respect to the relations between Russia and Austria, as well as with respect to the whole of Europe.
The Sound is one of the most important arteries of the world's commerce. About one hundred vessels of all nations pass daily through this strait, but only about ten (on the average, however, certainly larger ships) pass through the Suez Canal, which in the interests of the world's trade has become neutral.