(2) Boundary lakes and land-locked seas are such as separate the lands of two or more different States from each other. The boundary line runs through the middle of these lakes and seas, but as a rule special treaties portion off such lakes and seas between riparian States.[374]

(3) The boundary line of the maritime belt is, according to details given above (§ 186), uncertain, since no unanimity prevails with regard to the width of the belt. It is, however, certain that the boundary line runs not nearer to the shore than three miles, or one marine league, from the low-water mark.

(4) In a narrow strait separating the lands of two different States the boundary line runs either through the middle or through the mid-channel,[375] unless special treaties make different arrangements.

§ 200. Boundary mountains or hills are such natural elevations from the common level of the ground as separate the territories of two or more States from each other. Failing special treaty arrangements, the boundary line runs on the mountain ridge along with the watershed. But it is quite possible that boundary mountains belong wholly to one of the States which they separate.[376]

§ 201. Boundary lines are, for many reasons, of such vital importance that disputes relating thereto are inevitably very frequent and have often led to war. During the nineteenth century, however, a tendency began to prevail to settle such disputes peaceably. The simplest way in which this can be done is always by a boundary treaty, provided the parties can come to terms.[377] In other cases arbitration can settle the matter, as, for instance, in the Alaska Boundary dispute between Great Britain (representing Canada) and the United States, settled in 1903. Sometimes International Commissions are specially appointed to settle the boundary lines. In this way the boundary lines between Turkey, Bulgaria, Servia, Montenegro, and Roumania were settled after the Berlin Congress of 1878. It sometimes happens that the States concerned, instead of settling the boundary line, keep a strip of land between their territories under their joint tenure and administration, so that a so-called condominium comes into existence, as in the case of Moresnet (Kelmis) on the Prusso-Belgian frontier.[378]

§ 202. Whereas the term "natural boundaries" in the theory and practice of the Law of Nations means natural signs which indicate the course of boundary lines, the same term is used politically[379] in various different meanings. Thus the French often speak of the river Rhine as their "natural" boundary, as the Italians do of the Alps. Thus, further, the zones within which the language of a nation is spoken are frequently termed that nation's "natural" boundary. Again, the line enclosing such parts of the land as afford great facilities for defence against an attack is often called the "natural" boundary of a State, whether or not these parts belong to the territory of the respective State. It is obvious that all these and other meanings of the term "natural boundaries" are of no importance to the Law of Nations, whatever value they may have politically.

X STATE SERVITUDES

Vattel, I. § 89—Hall, § 42*—Westlake, I. p. 61—Phillimore, I. §§ 281-283—Twiss, I. § 245—Taylor, § 252—Moore, I. §§ 163-168, II. § 177—Bluntschli, §§ 353-359—Hartmann, § 62—Heffter, § 43—Holtzendorff in Holtzendorff, II. pp. 242-252—Gareis, § 71—Liszt, §§ 8 and 19—Ullmann, § 99—Bonfils, Nos. 340-344—Despagnet, Nos. 190-192—Mérignhac, II. pp. 366-368—Pradier-Fodéré, II. Nos. 834-845, 1038—Rivier, I. pp. 296-303—Nys, II. pp. 271-279—Calvo, III. § 1583—Fiore, I. § 380, and Code, Nos. 1095-1097—Martens, I. §§ 94-95—Clauss, "Die Lehre von den Staatsdienstbarkeiten" (1894)—Fabres, "Des servitudes dans le droit international" (1901)—Hollatz, "Begriff und Wesen der Staatsservituten" (1909)—Labrousse, "Des servitudes en droit international public" (1911)—Nys in R.I. 2nd Ser. VII. (1905), pp. 118-125, and XIII. (1911), pp. 312-323.

§ 203. State servitudes are those exceptional and conventional restrictions on the territorial supremacy of a State by which a part or the whole of its territory is in a limited way made perpetually to serve a certain purpose or interest of another State. Thus a State may by a convention be obliged to allow the passage of troops of a neighbouring State, or may in the interest of a neighbouring State be prevented from fortifying a certain town near the frontier.

Servitudes must not be confounded[380] with those general restrictions upon territorial supremacy which, according to certain rules of the Law of Nations, concern all States alike. These restrictions are named "natural" restrictions of territorial supremacy (servitutes juris gentium naturales), in contradistinction to the conventional restrictions (servitutes juris gentium voluntariae) which constitute the State servitudes in the technical sense of the term. Thus, for instance, it is not a State servitude, but a "natural" restriction on territorial supremacy, that a State is obliged to admit the free passage of foreign merchantmen through its territorial maritime belt.

That State servitudes are or may on occasions be of great importance, there can be no doubt whatever. The vast majority[381] of writers and the practice of the States accept, therefore, the conception of State servitudes, although they do not agree with regard to the definition and the width of the conception, and although, consequently, in many cases the question is disputed whether a certain restriction upon territorial supremacy is or is not a State servitude.

The theory of State servitudes has of late been rejected by the Permanent Court of Arbitration at the Hague in the case[382] (1910) of the North Atlantic Coast Fisheries between Great Britain and the United States, chiefly for the three reasons that a servitude in International Law predicated an express grant of a sovereign right, that the doctrine of international servitude originated in the peculiar and now obsolete conditions prevailing in the Holy Roman Empire, and that this doctrine, being little suited to the principle of sovereignty which prevails in States under a constitutional government and to the present international relations of Sovereign States, had found little, if any, support from modern publicists. It is hardly to be expected that this opinion of the Court will induce theory and practice to drop the conception of State servitudes, which is of great value because it fitly covers those restrictions on the territorial supremacy of the State by which a part or the whole of its territory is in a limited way made perpetually to serve a certain purpose or interest of another State. That the doctrine of State servitudes originated in the peculiar conditions of the Holy Roman Empire does not make it unfit for the conditions of modern life if its practical value can be demonstrated. Further, the assertion that the doctrine is but little suited to the principle of sovereignty which prevails in States under a constitutional government, and has, therefore, found little, if any, support from modern publicists, does not agree with the facts. Lastly, the statement that a servitude in International Law predicated an express grant of a sovereign right, is not based on any other authority than the contention of the United States, which made this unfounded statement in presenting their case before the Tribunal. The fact is that a State servitude, although to a certain degree it restricts the sovereignty (territorial supremacy) of the State concerned, does as little as any other restriction upon the sovereignty of a State confer a sovereign right upon the State in favour of which it is established.

§ 204. Subjects of State servitudes are States only and exclusively, since State servitudes can exist between States only (territorium dominans and territorium serviens). Formerly some writers[383] maintained that private individuals and corporations were able to acquire a State servitude; but nowadays it is agreed that this is not possible, since the Law of Nations is a law between States only and exclusively. Whatever rights may be granted by a State to foreign individuals and corporations, such rights can never constitute State servitudes.

On the other hand, every State can acquire and grant State servitudes, although some States may, in consequence of their particular position within the Family of Nations, be prevented from acquiring or granting some special kind or another of State servitudes. Thus neutralised States are in many points hampered in regard to acquiring and granting State servitudes, because they have to avoid everything that could drag them indirectly into war. Thus, further, half-Sovereign and part-Sovereign States may not be able to acquire and to grant certain State servitudes on account of their dependence upon their superior State. But apart from such exceptional cases, even not-full Sovereign States can acquire and grant State servitudes, provided they have any international status at all.

§ 205. The object of State servitudes is always the whole or a part of the territory of the State the territorial supremacy of which is restricted by any such servitude.[384] Since the territory of a State includes not only the land but also the rivers which water the land, the maritime belt, the territorial subsoil, and the territorial atmosphere, all these can, as well as the service of the land itself, be an object of State servitudes. Thus a State may have a perpetual right of admittance for its subjects to the fishery in the maritime belt of another State, or a right to lay telegraph cables through a foreign maritime belt, or a right to make and use a tunnel through a boundary mountain, and the like. And should ever aërostation become so developed as to be of practical utility, a State servitude might be created through a State acquiring a perpetual right to send military aerial vehicles through the territorial atmosphere of a neighbouring State. It must, however, be emphasised that the Open Sea can never be the object of a State servitude, since it is no State's territory.

Since the object of State servitudes is the territory of a State, all such restrictions upon the territorial supremacy of a State as do not make a part or the whole of its territory itself serve a purpose or an interest of another State are not State servitudes. The territory as the object is the mark of distinction between State servitudes and other restrictions on the territorial supremacy. Thus the perpetual restriction imposed upon a State by a treaty not to keep an army beyond a certain size is certainly a restriction on territorial supremacy, but is not, as some writers[385] maintain, a State servitude, because it does not make the territory of one State serve an interest of another. On the other hand, when a State submits to a perpetual right enjoyed by another State of passage of troops, or to the duty not to fortify a certain town, place, or island,[386] or to the claim of another State for its subjects to be allowed the fishery within the former's territorial belt;[387] in all these and the like[388] cases the territorial supremacy of a State is in such a way restricted that a part or the whole of its territory is made to serve the interest of another State, and such restrictions are therefore State servitudes.[389]

§ 206. According to different qualities different kinds of State servitudes must be distinguished.

(1) Affirmative, active, or positive, are those servitudes which give the right to a State to perform certain acts on the territory of another State, such as to build and work a railway, to establish a custom-house, to let an armed force pass through a certain territory (droit d'étape), or to keep troops in a certain fortress, to use a port or an island as a coaling station, and the like.

(2) Negative, are such servitudes as give a right to a State to demand of another State that the latter shall abstain from exercising its territorial supremacy in certain ways. Thus a State can have a right to demand that a neighbouring State shall not fortify certain towns near the frontier, that another State shall not allow foreign men-of-war in a certain harbour.[390]

(3) Military, are those State servitudes which are acquired for military purposes, such as the right to keep troops in a foreign fortress, or to let an armed force pass through foreign territory, or to demand that a town on foreign territory shall not be fortified, and the like.

(4) Economic, are those servitudes which are acquired for the purpose of commercial interests, traffic, and intercourse in general, such as the right of fisheries in foreign territorial waters, to build a railway on or lay a telegraph cable through foreign territory, and the like.

§ 207. Since State servitudes, in contradistinction to personal rights (rights in personam), are rights inherent to the object with which they are connected (rights in rem), they remain valid and may be exercised however the ownership of the territory to which they apply may change. Therefore, if, after the creation of a State servitude, the part of the territory affected comes by subjugation or cession under the territorial supremacy of another State, such servitude remains in force. Thus, when the Alsatian town of Hüningen became in 1871, together with the whole of Alsace, German territory, the State servitude created by the Treaty of Paris, 1815, that Hüningen should, in the interest of the Swiss canton of Basle, never be fortified, was not extinguished.[391] Thus, further, when in 1860 the former Sardinian provinces of Chablais and Faucigny became French, the State servitude created by article 92 of the Act of the Vienna Congress, 1815, that Switzerland should have temporarily during war the right to locate troops in these provinces, was not extinguished.[392]

It is a moot point whether military State servitudes can be exercised in time of war by a belligerent if the State with whose territory they are connected remains neutral. Must such State, for the purpose of upholding its neutrality, prevent the belligerent from exercising the respective servitude—for instance, the right of passage of troops?[393]

§ 208. State servitudes are extinguished by agreement between the States concerned, or by express or tacit[394] renunciation on the part of the State in whose interest they were created. They are not, according to the correct opinion, extinguished by reason of the territory involved coming under the territorial supremacy of another State. But it is difficult to understand why, although State servitudes are called into existence through treaties, it is sometimes maintained that the clause rebus sic stantibus[395] cannot be applied in case a vital change of circumstances makes the exercise of a State servitude unbearable. It is a matter of course that in such case the restricted State must previously try to come to terms with the State which is the subject of the servitude. But if an agreement cannot be arrived at on account of the unreasonableness of the other party, the clause rebus sic stantibus may well be resorted to.[396] The fact that the practice of the States does not provide any example of an appeal to this clause for the purpose of doing away with a State servitude proves only that such appeal has hitherto been unnecessary.

XI MODES OF ACQUIRING STATE TERRITORY

Vattel, I. §§ 203-207—Hall, § 31—Westlake, I. pp. 84-116—Lawrence, §§ 74-78—Phillimore, I. §§ 222-225—Twiss, I. §§ 113-139—Halleck, I. p. 154—Taylor, §§ 217-228—Wheaton, §§ 161-163—Bluntschli, §§ 278-295—Hartmann, § 61—Heffter, § 69—Holtzendorff in Holtzendorff, II. pp. 252-255—Gareis, § 76—Liszt, § 10—Ullmann, § 92—Bonfils, No. 532—Despagnet, No. 378—Pradier-Fodéré, II. Nos. 781-787—Mérignhac, II. pp. 410-412—Rivier, I. § 12—Nys, II. pp. 1-3—Calvo, I. § 263—Fiore, I. Nos. 838-840—Martens, I. § 90—Heimburger, "Der Erwerb der Gebietshoheit" (1888).

§ 209. Since States only and exclusively are subjects of the Law of Nations, it is obvious that, as far as the Law of Nations is concerned, States[397] solely can acquire State territory. But the acquisition of territory by an existing State and member of the Family of Nations must not be confounded, first, with the foundation of a new State, and, secondly, with the acquisition of such territory and sovereignty over it by private individuals or corporations as lies outside the dominion of the Law of Nations.

(1) Whenever a multitude of individuals, living on or entering into such a part of the surface of the globe as does not belong to the territory of any member of the Family of Nations, constitute themselves as a State and nation on that part of the globe, a new State comes into existence. This State is not, by reason of its birth, a member of the Family of Nations. The formation of a new State is, as will be remembered from former statements,[398] a matter of fact, and not of law. It is through recognition, which is a matter of law, that such new State becomes a member of the Family of Nations and a subject of International Law. As soon as recognition is given, the new State's territory is recognised as the territory of a subject of International Law, and it matters not how this territory was acquired before the recognition.

(2) Not essentially different is the case in which a private individual or a corporation acquires land with sovereignty over it in countries which are not under the territorial supremacy of a member of the Family of Nations. The actual proceeding in all such cases is that all such acquisition is made either by occupation of hitherto uninhabited land, for instance an island, or by cession from a native tribe living on the land. Acquisition of territory and sovereignty thereon in such cases takes place outside the dominion of the Law of Nations, and the rules of this law, therefore, cannot be applied. If the individual or corporation which has made the acquisition requires protection by the Law of Nations, they must either declare a new State to be in existence and ask for its recognition by the Powers, as in the case of the former Congo Free State,[399] or they must ask a member of the Family of Nations to acknowledge the acquisition as made on its behalf.[400]

§ 210. No unanimity exists among writers on the Law of Nations with regard to the modes of acquiring territory on the part of the members of the Family of Nations. The topic owes its controversial character to the fact that the conception of State territory has undergone a great change since the appearance of the science of the Law of Nations. When Grotius created that science, State territory used to be still, as in the Middle Ages, more or less identified with the private property of the monarch of the State. Grotius and his followers applied, therefore, the rules of Roman Law concerning the acquisition of private property to the acquisition of territory by States.[401] As nowadays, as far as International Law is concerned, every analogy to private property has disappeared from the conception of State territory, the acquisition of territory by a State can mean nothing else than the acquisition of sovereignty over such territory. It is obvious that under these circumstances the rules of Roman Law concerning the acquisition of private property can no longer be applied. Yet the fact that they have been applied in the past has left traces which can hardly be obliterated; and they need not be obliterated, since they contain a good deal of truth in agreement with the actual facts. But the different modes of acquiring territory must be taken from the real practice of the States, and not from Roman Law, although the latter's terminology and common-sense basis may be made use of.

§ 211. States as living organisms grow and decrease in territory. If the historical facts are taken into consideration, different reasons may be found to account for the exercise of sovereignty by a State over the different sections of its territory. One section may have been ceded by another State, another section may have come into the possession of the owner in consequence of accretion, a third through subjugation, a fourth through occupation of no State's land. As regards a fifth section, a State may say that it has exercised its sovereignty over the same for so long a period that the fact of having had it in undisturbed possession is a sufficient title of ownership. Accordingly, five modes of acquiring territory may be distinguished, namely: cession, occupation, accretion, subjugation, and prescription. Most writers recognise these five modes. Some, however, do not recognise prescription; some assert that accretion creates nothing else than a modification of the territory of a State; and some do not recognise subjugation at all, or declare it to be only a special case of occupation. It is for these reasons that some writers recognise only two or three[402] modes of acquiring territory. Be that as it may, all modes, besides the five mentioned, enumerated by some writers, are in fact not special modes, but only special cases of cession.[403] And whatever may be the value of the opinions of publicists, so much is certain that the practice of the States recognises cession, occupation, accretion, subjugation, and prescription as distinct modes of acquiring territory.

§ 212. The modes of acquiring territory are correctly divided according as the title they give is derived from the title of a prior owner State, or not. Cession is therefore a derivative mode of acquisition, whereas occupation, accretion, subjugation, and prescription are original modes.[404]

XII CESSION

Hall, § 35—Lawrence, § 76—Phillimore, I. §§ 252-273—Twiss, I. § 138—Walker, § 10—Halleck, I. pp. 154-157—Taylor, § 227—Moore, I. §§ 83-86—Bluntschli, §§ 285-287—Hartmann, § 61—Heffter, §§ 69 and 182—Holtzendorff in Holtzendorff, II. pp. 269-274—Gareis, § 70—Liszt, § 10—Ullmann, §§ 97-98—Bonfils, Nos. 364-371—Mérignhac, II. pp. 487-497—Despagnet, Nos. 381-391—Pradier-Fodéré, II. Nos. 817-819—Rivier, I. pp. 197-217—Nys, II. pp. 8-31—Calvo, I. § 266—Fiore, II. §§ 860-861, and Code, No. 1053—Martens, I. § 91—Heimburger, "Der Erwerb der Gebietshoheit" (1888), pp. 110-120.

§ 213. Cession of State territory is the transfer of sovereignty over State territory by the owner State to another State. There is no doubt whatever that such cession is possible according to the Law of Nations, and history presents innumerable examples of such transfer of sovereignty. The Constitutional Law of the different States may or may not lay down special rules[405] for the transfer or acquisition of territory. Such rules can have no direct influence upon the rules of the Law of Nations concerning cession, since Municipal Law can neither abolish existing nor create new rules of International Law.[406] But if such municipal rules contain constitutional restrictions on the Government with regard to cession of territory, these restrictions are so far important that such treaties of cession concluded by heads of States or Governments as violate these restrictions are not binding.[407]