[219] The Drago doctrine originates from Louis M. Drago, sometime Foreign Secretary of the Republic of Argentina. See Drago, "Cobro coercitivo de deudas publicas" (1906); Barclay, "Problems of International Practice, &c." (1907), pp. 115-122; Moulin, "La Doctrine de Drago" (1908); Higgins, "The Hague Peace Conferences, &c." (1909), pp. 184-197; Scott, "The Hague Peace Conferences" (1909), vol. I. pp. 415-422; Calvo in R.I. 2nd Ser. V. (1903), pp. 597-623; Drago in R.G. XIV. (1907), pp. 251-287; Moulin in R.G. XIV. (1907), pp. 417-472; Hershey in A.J. I. (1907), pp. 26-45; Drago in A.J. I. (1907), pp. 692-726.
[220] See Scott in A.J. II. (1908), pp. 78-94.
Admissibility of Intervention in default of Right.
§ 136. In contradistinction to intervention by right, there are other interventions which must be considered admissible, although they violate the independence or the territorial or personal supremacy of the State concerned, and although such State has by no means any legal duty to submit patiently and suffer the intervention. Of such interventions in default of right there are two kinds generally admitted and excused—namely, such as are necessary in self-preservation and such as are necessary in the interest of the balance of power.
(1) As regards interventions for the purpose of self-preservation, it is obvious that, if any necessary violation committed in self-preservation of the International Personality of other States is, as shown above (§ 130), excused, such violation must also be excused as is contained in an intervention. And it matters not whether such an intervention exercised in self-preservation is provoked by an actual or imminent intervention on the part of a third State, or by some other incident.
(2) As regards intervention in the interest of the balance of power, it is likewise obvious that it must be excused. An equilibrium between the members of the Family of Nations is an indispensable[221] condition of the very existence of International Law. If the States could not keep one another in check, all Law of Nations would soon disappear, as, naturally, an over-powerful State would tend to act according to discretion instead of according to law. Since the Westphalian Peace of 1648 the principle of balance of power has played a preponderant part in the history of Europe. It found express recognition in 1713 in the Treaty of Peace of Utrecht, it was the guiding star at the Vienna Congress in 1815 when the map of Europe was rearranged, at the Congress of Paris in 1856, the Conference of London in 1867, and the Congress of Berlin in 1878. The States themselves and the majority of writers agree upon the admissibility of intervention in the interest of balance of power. Most of the interventions exercised in the interest of the preservation of the Turkish Empire must, in so far as they are not based on treaty rights, be classified as interventions in the interest of balance of power. Examples of this are supplied by collective interventions exercised by the Powers in 1886 for the purpose of preventing the outbreak of war between Greece and Turkey, and in 1897 during the war between Greece and Turkey with regard to the island of Crete.
[221] A survey of the opinions concerning the value of the principle of balance of power is given by Bulmerincq, "Praxis, Theorie und Codification des Völkerrechts" (1874), pp. 40-50, but Bulmerincq himself rejects the principle. See also Donnadieu, "Essai sur la théorie de l'équilibre" (1900) where the matter is exhaustively treated, and Dupuis, "Le principe d'équilibre et le concert européen" (1909), pp. 90-108, and 494-513. It is necessary to emphasise that the principle of the balance of power is not a legal principle and therefore not one of International Law, but one of International policy; it is a political principle indispensable to the existence of International Law in its present condition.
Intervention in the interest of Humanity.
§ 137. Many jurists maintain that intervention is likewise admissible, or even has a basis of right, when exercised in the interest of humanity for the purpose of stopping religious persecution and endless cruelties in time of peace and war. That the Powers have in the past exercised intervention on these grounds, there is no doubt. Thus Great Britain, France, and Russia intervened in 1827 in the struggle between revolutionary Greece and Turkey, because public opinion was horrified at the cruelties committed during this struggle. And many a time interventions have taken place to stop the persecution of Christians in Turkey. But whether there is really a rule of the Law of Nations which admits such interventions may well be doubted. Yet, on the other hand, it cannot be denied that public opinion and the attitude of the Powers are in favour of such interventions, and it may perhaps be said that in time the Law of Nations will recognise the rule that interventions in the interests of humanity are admissible provided they are exercised in the form of a collective intervention of the Powers.[222]
[222] See Hall, §§ 91 and 95, where the merits of the problem are discussed from all sides. See also below, § [292], and Rougier in R.G. XVII. (1910), pp. 468-526.