[893] Concerning hostages nowadays taken in time of war, see below, [vol. II. §§ 258]-259.
Pledge.
§ 526. The pledging of movable property by one of the contracting parties to the other for the purpose of securing the performance of a treaty is possible, but has not frequently occurred. Thus, Poland is said to have pledged her crown jewels once to Prussia.[894] The pledging of movables is nowadays quite obsolete, although it might on occasion be revived.
[894] See Phillimore, II. § 55.
Occupation of Territory.
§ 527. Occupation of territory, such as a fort or even a whole province, as a means of securing the performance of a treaty, has frequently been made use of with regard to the payment of large sums of money due to a State under a treaty. Nowadays such occupation is only resorted to in connection with treaties of peace stipulating the payment of a war indemnity. Thus, the preliminary peace treaty of Versailles in 1871 stipulated that Germany should have the right to keep certain parts of France under military occupation until the final payment of the war indemnity of five milliards of francs.
Guarantee.
§ 528. The best means of securing treaties, and one which is still in use generally, is the guarantee of such other States as are not directly affected by the treaty. Such guarantee is a kind of accession[895] to the guaranteed treaty, and a treaty in itself—namely, the promise of the guarantor eventually to do what is in his power to compel the contracting party or parties to execute the treaty.[896] Guarantee of a treaty is a species only of guarantee in general, which will be discussed below, §§ [574]-576a.
[896] Nippold (p. 266) proposes that a universal treaty of guarantee should be concluded between all the members of the Family of Nations guaranteeing for the present and the future all international treaties. I do not believe that this well-meant proposal is feasible.